Large dump of my ideas/thoughts

Amoeba movement:

My main concern is how psuedopods will function. once a certain point is reached when it comes to the rigidity of your cell. How will your cell move? Currently the standart rigidity results in a fairly stagnant cell body which doesnt move and spread out much (which im assuming will change later on throughout the games development). this makes it so your cell appears fairly uniform and locomotion is quite simple as it just looks like your cell is merely swimming.

However. pseudopodia seem to be much less intuitive as in real life they are usually quite spread out giving them quite alot of variation in shape. How would this type of locomotion work? and where would the camera be centered at? would pressing the directional keys create a ‘current’ inside your cell pushing out numerous pseudopods? it seems far more convoluted than the much more conventional form of locomotion.



Omnicron pointed out to me that amoeba movement will most likely be like QWOP/mount your friends. with pseudopodia capable of being activated and moved. Having the controls of the game suddenly switch from simple directional keyboard movement to qwop seems like a bit of a drastic measure and would probably disrupt the flow of the game for a while as the player gets used to the new controls. not to mention the fact that this would be quite hard to get used to making what should be a simple and easy to understand evolution simulator into another octodad/i am bread. simpler more ergonomic controls which should probably remain fairly constant throughout the game seems much more simpler and easier to develop.


So currently it appears that unlocking organelles will be based on engulfing bacteria which are capable of certain tasks.

for eg: chloroplasts will be obtained by engulfing and forming a symbiotic relationship between photosynthetic bacteria. judging from the dev forums it appears unlocking organelles will be based purely on RNG. by this i mean there is a small percentage where engulfing a bacteria will unlock the organelle. this while certainly fairly realistic, makes it so that casual players will probably not be able to know to engulf bacteria to unlock organelles.

There are a few issues i see with this RNG based unlocking of organelles:

  • Unless there is implementation of a guide which tells the player how to unlock organelles, there is a low chance they will naturally encounter this if the percentage is fairly low.

  • People attempting to 100% the cell stage will usually have to grind in order to unlock all the organelles they require. difficulty is fun and all, but there will always be a certain point where it is not difficult but instead grindy.

  • Unlike spore. which granted a new body part every time a species with that body part died. Thrive relies on chance making it unreliable and undependable.

What im basically attempting to say is that using RNG to determine whether you do or dont unlock an organelle will be a tricky thing to manage. setting the percentage too high will make the game quite easy, and setting it too low will make it too grindy. there will need to be constant tweaking to find an equillibrium. which is why i believe that there should be special bacteria which unlock organelles.

what do i mean by this? well. Unlike using RNG. the special bacteria will actually look unique and different from its companions giving players an incentive to investigate. this can easily be done by outlining the bacteria in bold yellow or some other visual effects. Once this special bacteria is engulfed the player will hear a special sfx and a pop-up will appear and show that they have unlocked a certain organelle.

Why would this design be better? lets compare it.

  • Special bacteria looks special. no need for immersion breaking tutorials/walls of test. there will already be an incentive to investigate the bacteria and once the player engulfs and reads the popup they will understand that these Special bacteria are key to unlocking organelles.

  • people attempting to 100% the cell stage may or may not find this new method more time consuming. however, unlike the previous method. this current method gives them a goal/destination they must reach (the special bacteria) and does not force them to blindly chase and absorb bacteria for a chance to unlock an organelle.

  • The special visual cue’s will basically make it so you know what bacteria will 100% give you the unlock.

so where would these special bacteria be found? will they be frozen in place littered around the world like spores meteorites?

well. really they’re just like shiny pokemon. they’re basically exactly the same as normal bacteria except for the fact that they have a special visual cue and unlock organelles. they still act the same way as any other bacteria of the same species.

Increasing or decreasing the difficulty of the game would also dictate how many of these shiny bacteria spawn. a harder game will result in less shiny bacteria being spawned. and an easier game will result in more shiny bacteria being spawned.

Here is a concept animation/gif of my idea: (a mitocondrion like cell is being engulfed)


Organelle upgrades

Now im not sure if this idea has been brushed upon previously. but i think that organelles. (eukaryotic organelles which originate from bacteria) should be able to be upgraded. this is mainly due to the fact that if we look at it realistically; the bacteria Symbiant wouldn’t have been perfectly specialized as soon as it was engulfed. these organelles would’ve had to evolve along side the host cell.

Other things would be evolutionary pathways for the organelles.

for eg: pili in thrive are an extremely diverse group of organelles which can be broadly described as “stabby sticks” they can be used for predation, genetic sharing, and a plethora of other things. ive never seen people go much in depth when talking about pili and so i would like to give my breif ideas of a pili ‘skill’ tree.

membrane pilus

allows you to stick on surfaces.

Predatory pilus

simple as it can be. this pilus stabs other creatures

by spending Mutation points. predatory pilus is able to evolve into:
(you will be able to unlock these once you place a predatory pilus down and spend MP on evolving the pilus)

Injector pilus

a much stronger varient of the predatory pilus mroe specialized and capable of injecting prey with harmful agents.

sexual pilus

you are able to perform genetic swapping increasing your mutationpoints

this idea is merely a daydream so it hasnt really been thought about much.


IIRC one of the ideas was to have a movement comparable to something like mount your friends / QWOP, where your cell has a couple ‘tentacles’ which you can ‘activate’ by pressing their corresponding buttons, after which you can move them, with the rest of your cell following suit.

That’s the point, it should be difficult to acquire every single possible organelle. There’s a reason cells IRL don’t have that.

‘no need for immersion breaking tutorials, just immersion breaking popups’
Something is funky here.

Buyt yeah IIRC the plan is to have a couple unique organelles that exist purely to endosymbiosify.

As for your pili ideas, check this pretty old thread on the dev forums, which gave the following ideas for pilus mutations:


I think the grapple pilus would lead to a lot of different play styles, personally that’s the one I’d like in game the most.


Just dropping in to critique some of the planned features of the game.


Ive said it before, and i will say it again. the currently hypothesised means of Amoeboid movement (which Omnicron has recently notified me of) is an extremely poor design choice.

Apparently. pseudopodia ‘tentacles’ are going to be capable of being stretched/moved by using keybindings. While this would certainly make your cell look like an amoeba. the cluttered new controls and sudden switch from traditional directional movement to peculiar QWOP esk controls would greatly disrupt the flow of the game for the player as the player would learn to adjust to the new controls.

here is a visual demonstration of how unintuitive this means of movement would be:

The highlighting of the letter A is a representation of the activation of the pseudopodia, and the arrow represents the directional key(s) being pressed after the pseudopodia is activated…

Why would there have to be numerous pseudopodia tentacles which had to be activated before being moved when instead you could get much simpler and easier controls by just sticking with 1 single permanently activated pseudopodia? all it would do is complicate the control mechanics and turn thrives cell stage into a 2d cell version of octodad.

Unlike the current streamlined and conventional swimming mechanics. this amoeboid movement concept doesn’t work at all.

I also wanna use this new post to reply and try to answer some of the questions and misunderstandings i may have caused with my post.


When i mentioned “immersion breaking tutorials” i was attempting to relate back to walls of text which would have paused the game. heres an animation i made indicating what i was trying to convey:


my main issues were having the game pause pulling the player out of the experience. there is quite a stark difference between a wall of text which pauses the game and basically forces you to read it in order to proceed and understand what to do. And a simple popup that alerts you of something in real time before disapearing.

i personally believe that thrive would benefit greatly from a fairly ‘hands off’ approach when it comes to trying to tutor the player. small little pieces of game design which subtly hint the next appropriate step for the player. however i know undoubtably that this mindset/philosophy of: “show don’t tell” wouldn’t be able to be always closely followed due to thrives depth and complexity.

Maybe pseudopodes would be used as a trap for cells. Amoeba generally trap cells instead of hunting them by moving itself IIRC.
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I do agree with a lot of what you have mentioned. Having the unlocking of certain organelles be based on random chance doesn’t sound like a smart idea, and I don’t believe it bodes well for representing the continuity of evolution. I feel the same extends to mutation points, to an extent, as well. Most games rely on a sense of progression as a major component of why said game is fun, re-playable, and varied. I had a thought which I had posted in a discussion here:
Progressive Upgrades Leading to Unlocking Features (Renamed from "Skill-Tree" Thread)
which basically suggested the addition of some sort of unlocking system akin to a “skill tree” of a sort, which could be optimized to encourage a wise allocation of mutations to adapt to your environment in a way that seriously reduces the problem of organ gluttony, while demonstrating a continuous derivation of morphology from precursor structures as is seen in real-world evolution.
Of course, unlocks are not necessarily representative of how evolution works, but I feel that it’s much better than simply being limited by a point system, which allows for the problem of organ gluttony and random jumps in cell function which just don’t make sense or don’t feel significant or earned under MP; for example, going from prokaryotic to eukaryote just by saving up for a nucleus, which feels rather underwhelming I feel… Wouldn’t it be cooler if you earned a nucleus by unlocking certain aspects of your cell - - such as the cytoplasm, mitosis, and the membrane - with many different “upgrade paths” being offered to you until you worked up to said nucleus, hence adding so much more depth and diversity to a game which prides itself on replay-ability?

In the discussions I had with devs, it sounds like they have some sort of progression system being worked on behind the scenes, so they might just be using mutation points as a simple game mechanic until this system is fully developed; if so, I think it would be cool if they revealed some of this thinking, as it could seriously hype up the forums, I feel.


So currently I don’t think there is a progression system being worked on, mostly because I am not sure it’s a good idea.

I think one problem with things like skill trees are that you commit to a certain playstyle after a while. Like say you go down the chloroplast + cell wall route, once you have paid a lot into unlocking that you are kind of stuck as a plant and it would be hard to become a predator because the other cells would have become specialised with powerful unlocks at that point.

I think personally I always go back to the example of how Kerbal Space Program sandbox mode is better than career. The reason is that having a lego set out of which you can build anything and then being given a bunch of hard and interesting problems to solve is a really fun way to play. Grinding missions to unlock stuff was definitely less interesting imo, though it was maybe easier for new players to figure out.

The current idea for Thrive is to have the environment changing and the other species changing such that you are always needing to think and adapt every time you go to the editor to try and stay in the game. If you became static for too long other species would evolve to prey on you and resist all your attacks so you need to keep updating. Also you can work your way towards a larger and more complex cell. I think that should make the game interesting, though it will be hard to balance.


Looking at your original post ive decided to actually try to animate something which vaguely imitates your original idea:


you can probably already see the similarities to the evolution tree in ancestors.

i can see how your specialization is quite different from a skill tree. however linear progression is inevitable or rather. It would be inevitable for the evolution of certain things such as the nucleus.

ive tried my best to make this animation show the possibility’s and show how not everything would be linear by taking some liberties. the locked primary evolution points (the big cyan circles with holes inside them) are locked. which when unlocked would display more secondary evolution points. (the dark gray points with lines connecting them) These primary evolution points could be unlocked through certain events like endosymbiosis. and unlocked with them would be secondary evolution points which grants specialization.

that was probably quite hard to understand so allow me to paraphrase by giving an example

Lets say we undergo endosymbiosis and engulf a mitochondrion like cell. This would unlock a Primary evolution point (P.E.P) and allow for us to specialize this mitochondrion symbiant. (seen here through the gray secondary evolution point)

by unlocking and evolving one of these specialization you would lock the other secondary evolution point, thus reducing overpowered and glutton cells.


I think @TJwhale made some solid points when he talked about commitment to a certain playstyles after investing many mutation points. which is why i made the decision to implement numerous Primary Evolution points with short branches which would make re-specialization much easier.


Very good points and ideas in the past two posts.

I definitely see what you mean, although looking through the KSP discussion posts on Steam, it seems like a lot of players are split in terms which mode is better. Many people enjoy the freedom that comes with sandbox, but there is also an opposite sentiment in that the freedom given by sandbox becomes boring after a while due to a loss of difficulty or a lack of a clear objective. Many people also enjoy career mode due to the depth and rewarding feeling that comes with progression, but many also comment that it can feel like a grind half the time.

So, there are definitely flaws and benefits with both approaches; that isn’t a question. I think the question, however, is which of these system’s benefits and problems would best benefit Thrive, and so far, I think that the no-limit freedoms of Thrive have been a detriment as opposed to a benefit to Thrive, due to problems that come with organ gluttony and a feeling of insignificance upon the accomplishment of certain evolutionary feats.

Thrive is different from KSP in that Thrive’s objective is making a game out of a biological progress that is essentially the progression of biological traits into more effective traits through many small adjustments to morphology. There is no linearity in the sense that there is no one ultimate lifeform that succeeds in all situations and that there is no goal that evolution is working towards, but there is linearity in the sense that all parts/behaviors are derived from other parts/behaviors. KSP on the other hands isn’t trying to simulate anything else other than space-flight; they aren’t interested in recapturing the history of space flight or all the possible ways that spaceflight could have been different if different developments occurred, their objective was just to create a game that abided to laws of physics. Science mode and Career mode were additions much later in the development cycle of KSP as a result of this objective, as they weren’t really concerned with these modes until they already achieved a perfect space program sandbox.

Yes, that is a problem that comes with a traditional skill tree. In most games, skill trees are basically created with a goal in mind, it being the unlocking of all the skills in a player’s resume. Batman: Arkham games come to my mind when I think of this: as does Skyrim. However, it is undeniable that these tech trees are the major underlying balancing mechanism in those games.

For example, if Skyrim played by the rules of Thrive as is currently established, you wouldn’t have to go through many weaker skills to get to those cool powers; for example, via Thrive rules, you could just go straight to being able to craft dragon armor without having to go through the various stepping stones that would reasonably seem to be on the way to such a capability, such as being able to upgrade leather armor, then craft iron armor, then upgrade iron armor, etc. Skyrim also includes this skill tree in a way that doesn’t identify a certain warrior type as being superior to another; for example, a mage isn’t weaker than a warrior at any given moment, although a specialized warrior could beat a novice mage. You did mention that you envisioned an environment that basically acts as the inhibiting factor/sense of progression; still, what would stop a player from just basically having one of every organelle or spamming a single organelle all the time, and what would stop a beginner player from bee-lining towards a nucleus within the first few minutes of a game? Doesn’t it seem like there should be so much more going on between the beginning of a game and the nucleus?

I thought about how a skill-tree esque system could help create a sense of meaningful progression and derivation of parts from other parts while also appealing to a sense of creativity and freedom. After looking at Death’s concept, which is very well done, I had a bit of a thought tank.

My basic thought was: what if a player was given a limited amount of “investment points” in the beginning of the game, that they would have to wisely implement in various aspects of their cell’s morphology? Mutation points within the editor would remain, which would act as the currency for the implementation/removal of organelles; but, the unlocking/upgrading capabilities of organelles within the cell would be based on the investment of these points. Over time, these investment points will increase upon the success of your species (maybe a not so successful species is granted 1 IP, while a successful species is granted 2 IP), which could allow you to either progress further down certain upgrade path or go back and invest in less developed upgrade paths to unlock more diverse features. You could also de-invest IP to re-distribute points, which could help with the issue of being too far invested within a certain path.

For example, let’s say I’m a predator cell in an arms race with a herbivore that has a thick membrane. When I go to the editor, I spend IP to upgrade my pilus into a more robust pilus which can penetrate thicker membranes, because I have extra IP. I then go to the regular cell editor and use MP to place however many pilus I desire. My species does well, and as a result, I earn IP more rapidly, which I invest in my mitochondria aspect of my cell, which allows me to place more mitochondria or make my existing mitochondria more efficient. Later however, a speedy cell emerges which I can’t catch, which is problematic for me because I am still adapted to prey on those thick membrane cells, and as a result, I can’t compete as well. So, I make a decision to de-invest in the thick pilus path to redistribute IP into the mobility aspect of my cells, which grants me the ability to place flagellum, but takes away my ability to place sharper pilus.

Another example. Let’s say I’m a cell doing decently well, with flagella that allows me to move fast; unfortunately for me however, temperatures dropped all over the world, and ice started developing. I decide to de-invest in flagella due to the burden of its energy costs to invest in a thicker membrane, which allows me to remain as an efficient energy producer.

And another example. Let’s say I just started a game as that blob of cytoplasm that zooms around eating food. As my species grows, I get IP that I can invest in various features of my cell which will help me to unlock various structures; however, I don’t have enough IP to reach the nucleus yet, so I remain a prokaryote, wisely investing in the various prokaryotic functions that I do have. As my species advances however, I earn more and more IP, which I could invest in either diversifying my specie’s features, or just spend going for the nucleus.

Looking at Death’s beautiful gif concept detailing a skill tree, imagine progression down those skill tree lines being based on the distribution of these IP. I feel that you’ve already basically envisioned a system such as this through your concept, I just felt that a more detailed concept was in order.

I am sure that there are many potential problems with this concept, but I feel like this could be a starting point for a more advanced concept that serves as the compromise between player autonomy and progression.


Taking the example of Skyrim it would be totally possible to balance it such that all abilities were available from the start.

For example for warriors there could be light, heavy and dragon armour which gives you 10, 20 and 30 defence but also slows you down by 20, 40 or 60% respectively. That way you have to choose between the tradeoffs.

And maybe all spells are available, so there’s spark which does 5hp of electric damage and costs 5 Mana and there’s Max Fireball which does 100hp of fire damage, has a 2% chance of setting you on fire and costs 90 Mana. That way you can let the player make any build with any set of spells, abilities, weapons or armour right from the start and respec or change equipment any time they like.

So it’s just about how you balance it rather than some fundamental thing about the game. I do agree though that if you balanced Skyrim like this then a lot of the motivation to explore for XP would be taken away, progression would be less exciting.

Re organelle gluttony I think that’s a good example of a problem which can’t be solved by unlocks. Because if it’s better to have more organelles then all unlocks / progression will do is just slow down the process of growing too large. It will still happen, just slower.

What it needs is fixing such that you can’t be too big. For example one thing we haven’t done yet but may well do is have osmoregulation cost scale faster than linearly. That way there is a penalty to being really large so you have to tradeoff organelles vs their usefulness. That is a much better approach imo because then it actually fixes the problem rather than just slowing it down.

I’m not totally against progression as a general concept and I think it may well have a place in the game. There’s already a bunch of stuff behind the nucleus and in this release we’re hoping to have a dynamic system which will turn off organelles which are useless to the player which will mean there is even less available at the start.

I also think that by giving up the sandbox approach the game loses something quite profound.


I feel like having Thrive solely be defined as a sandbox game seriously diminishes the evolution simulation aspect of the game design, however.
For the hands-on abstract playstyle that you love in sandbox KSP, which uses the harshness of simulated gravity to demonstrate how difficult yet glorious space-flight is, it does make sense that the absolute lack of creative restraint compliments sandbox KSP. In KSP sandbox, the challenge is not found in continuously trying to adapt to everchanging conditions, it is just to achieve a goal that always faces the same foe found in gravity. Moreover, there is not really an emphasis on progression in KSP to the extent at which progression is emphasized in Thrive, as Thrive is simulating evolution, which depends on the presence of changing situations and changing competition. In KSP, the conflict is found in trying to overcome a constant yet troublesome obstacle that never changes – gravity - to go to troublesome places that also never change.
Therefore, the progression, fun, success, and simulation aspects of KSP are not really dependent on making the best of/most innovative use of what you have as is found in the many wonderous products of evolution through out history, as KSP is not attempting to demonstrate something that is constantly fluctuating. Progression in KSP, and thus space-travel, is measured by a sense of chipping away at this overwhelming force that is gravity, without worrying about competition or environmental conditions, which are fundamental blocs of evolution.
If Thrive was simply attempting to simulate an microbe ecosystem without the context of evolution sprinkled in, then I definitely agree that a KSP-esque sandbox setup would be the best way to structure the game; however, because evolution is the epitome of Thrive’s game design, and in turn competition with the environment and other cells is the hallmark of evolutionary theory, this unrestricted sandbox philosophy doesn’t seem like the best way to go about simulating the game’s target.
I agree with you that organ gluttony can’t be simply solved by investment of upgrade points; osmoregulation does sound like a good idea that could work, and I don’t see a reason why its inclusion can’t work with progression. However, you agree with me, as we both agree that progression can add a lot more depth and excitement to a game, as is seen in your Skyrim example. For now, forget the whole balancing sentiment behind concepts of progression, as there seems to be other better ways of achieving this balance; is there a reason that the freedom found in a sandbox, which demonstrates the diversity of life, can’t co-exist with a progression system, which demonstrates the evolution of life? Can we not add a feeling of depth, which can magnify the fun and achievement felt in Thrive, while allowing a large amount of freedom to the depth that you have? I feel like a variation of the IP concept system in the above post and the ideas given by Death throughout this topic could easily be altered in a way that preserves the evolutionary depth that is offered by the original concepts and the freedom that comes with lax design restrictions.


Yeah I think that is a good point. The current plan is to balance things without progression; get the auto evo system working and the environment changing, make it hard to get energy etc. Then we can see where we’re at and if it would make sense to add something in.


Remember, evolution is descent with modification. The more fundamental a feature is, the more difficult it is to alter. Humans could evolve to have larger ears, for example, as that is a slight modification of an existing and relatively recent feature. Humans could not, however, evolve to be comprised of plant cells instead of animal cells, as that is too fundamental to human biology. In that regard, I think there must be a mix of sandbox and progression systems. There must be some progession, of course. Prokaryote to eukaryote, unicellular to multicellular, etc.

I usually oppose addition of abstract currencies (the mana of Paradox games is an illustrative example), as they are arbitrary. As such, I do not want there to be skill points (or whatever they might be called) in Thrive. Moreoever, skill trees are inherently linear, and they are the same each time the game is played. The player is forced to follow this path every time. Perhaps I have an idea for a cool creature, but first I must grind to get enough skill points to unlock all the parts. This is not fun. Deus makes a good point that the environment of KSP never changes. Because Thrive’s gameworld will change (and dynamically at that, so it will not be the same every time), the sandbox design is much more appropriate. If a dynamic change in the gameworld requires an adaptation that is locked behind some arbitrary node on some arbitrary skill tree, then the player would have no chance and be forced to die merely due to arbitrary game design.

I think adaptations should build on each other, with more complex ones requiring simpler ones to function. That way, if the player wants to change something fundamental, the complex features must first be removed, which is costly, time-consuming, and unlikely to be successful. Alternatively, existing features an be repurposed. Whales have the same hand bones as humans, as they share a common mammalian ancestor, and adapting existing mammalian forelimbs into flippers was easier than deleting and replacing the existing limbs. This can lead to evolutionary cul-de-sacs, as with emus. Emus’ forelimbs are useless; they do not even have muscles. Those arms, then, cannot evolve into something more useful, as there is nothing for evolution to work on.

Everything has a cost and a benefit, and the game must be balanced in such a way that even tiny advantages can yield great results over a long enough period. Insect wings began as nubs on the thorax. Those nubs were useless for flight and offered almost no advantage over other insects’ thoraxes, but the miniscule advantage scaled massively over millions of years. There must be fierce, cutthroat competition with other species. Making energy scarce makes sense for some species (e.g. apex predators), but it is not sensible for others (e.g. epipelagic photosynthesizers), so it should not be the only factor which decides success.

When in doubt, consult reality instead of making arbitrary currencies. Why can unicellular organisms not become enormous (stentors and slime molds notwithstanding)? The scientific answer would be much more satisfying than an arbitrary “because the game designers say so.”


That sound’s like a good idea. If the game resembles evolution well enough with these fundamental aspects of the game established, a very complex progression system isn’t really needed.

A skill tree doesn’t necessarily have to be completely linear; there can be several various different paths that a player could travel down which are not necessarily better than the other but benefits the player more in the current example. For example, one path you could invest in could be shaggy fur, while another could be a smooth, scaly skin texture. With the points you have available, you could either invest in a bit of both, invest more in one, or invest fully in one path. Further upgrades could be based on this allocation; perhaps if you invest enough in fur, you can get porcupine spikes, or keratin plates akin to a pangolian; if you invest enough in scales, you could get some form of horns, or feathers. If there are 3 variations in three different features of your organism, there are already 27 different variations; imagine how many variations would be possible if a lot of parts had balanced “skill-tree paths”. A more robust progression system than the one discussed in this forum would have to be detailed and implemented to account for all possible instances if the developers do decide to use complex progression, but the IP system could be a decent start.

Also, to an extent, if you have a specific creature in mind, it wouldn’t be ideal if you could just get there with a few steps if we want Thrive to be a decently long and in depth game; if you want some sort of eagle-esque creature for example, you will first need to develop wings, which need things such as feathers/extensive layers of skin, a body design that allows for rapid flight, etc. The progression system, if implemented, should be limiting not to prevent a player from designing what they want with what they have, but realistically demonstrating that evolution is a process of using what you have at the current moment to its best and most innovative extent, with the understanding that what you have now could either be useless or essential in a future environment. You are right that Thrive does need to stay away from a huge amount of grinding . That’s when the sandbox aspect of the game needs to kick in. If a player has the parts that they need “unlocked”, the only limiting factor in achieving the creature they want should then be MP and osmoregulation/Square Cube Law, not them not being able to have all of the parts they need unlocked. With proper fine-tuning of MP and IP if the design was chosen, I feel like this could be achieved.

I feel like a finely-tuned IP/progression system could be used to represent this. Is there something about progression that you feel doesn’t appeal to this?

You’re right, there shouldn’t be an inherent cap to crazy, outlandish features. I remember hearing about a huge unicellular organism, around the size of a smaller beach ball, that exists on the ocean floor. In this case, the only thing that should limit this feature is osmoregulation, which could exist in tandem with a progression system and MP.