Now I know that this will be a very long time from now but I think its best a say it now so that it can be possibly added in the future without to much hassel. However, what I am suggesting will, if possible to be added, could very well make the biggest defference over “Spore” that Thrive can make and also would make it a way more scientifically accurate game.
Gravity and Planet size: Now a lot of people would think that this would not be a very necessary thing for a game like this but they couldn’t be more wrong. This would affect EVERYTHING from the density of water in the cell stages, to the shape of the organisms on the surface, to even the difficulty of actually escaping orbit. Almost everything that the planet would evolve would be based heavily on its gravity. Planets sizes also would play a large part in what could evolve because of the amount of resources available to its inhabitants. These two forces are indeed similar but gravity is based on mass while size is based on volume, the difference is like a Blue Gaint to a black hole. A black hole with the same mass as a Blue Gaint would be significantly smaller than the Blue Gaint because it is so dense that it has a lot less volume but would still have the same gravity. This means that these should be two different things in Thrive as well if it is decided to add world modification options at all. A larger planet also means more space for spieces to expand to while a smaller planet is the reverse.
Atmospheric and Ocean Densities: This would affect quite a few things things. One; what exactly would float and what would not, both in the sea and in the air. A super dense atmosphere would make it so larger organisms could fly/swim through the air while a super sparse atmosphere would make it so almost no organisms could fly. A super dense ocean though would make it so that it would be very difficult to survive the pressures at the sea floor which would induce a number of things such as a lack of bottom feeders.
Two; radiation and sunlight levels. A super light atmosphere or ocean would also make the creatures more susceptible to UV and other forms of radiation while a super dense atmosphere would make it so almost no sunlight would reach the surface meaning life would have to find other ways of finding energy.
And three; composition. Meaning what they would evolve to breathe or more accurately how they evolve to breathe. A super dense atmosphere may have a large amount of toxins in the air that would need to be filtered out while a super light atmosphere may not have much oxygen in it so a way of taking in more air would be needed. Same would go for the oceans, they may not be as much H2O as our oceans are and thusly could be fairly toxic to life or the water may not have enough oxygen levels in it to support some lifeforms.
Planetary rotation speed: This one is almost the most important thing for any life on a planet. Firstly this would affect windspeed on the planet, with faster the rotation the greater the windspeed. Meaning life would have to evolve in order to deal with greater windspeed such as making themselves closer to the ground or having smooth exteriors.
Secondly, the day/night cycle. A planet with a quick rotation would have shorter days and night while a slow rotation means longer days and nights. The longer the day the more the star the planet orbits has time to warm the surface of the planet and the longer the night the more a planet can cool down. So say a planet has a rotation that permanitly sets one side of the planet facing the star and the other side facing space. The side facing the star would be completely baked and extremely hot while the otherside would be completely frozen over. This would leave only the most narrow of bands stretching from pole to pole in which life could survive without boiling or freezing.
Distance from the Star: This would be relative to the heat given off of the star but would ultimately affect the planet’s temperature. Everyone knows this though so mild explanation for those who don’t. The closer to the star the hotter the planet and the further from it the colder the planet.
I would love to see more comments like this one on maybe a few things a forgot or even to correct me on the things I got wrong. I did this completely off the top of my head so there are bound to be more than a few errors in it but this is just to get y’all thinking about how much a planet can affect life on it.