So the game would originate with a cell that has an Ameboid cell membrane and no cell walls. once you undergo mitosis and enter the cell stage there will be a membrane tab. if you click on it you will notice 3 things: the membrane type group, the cell wall type group, and the strange purple bar on the left.
The membrane type group acts as a range for how much you can mess around with your purple rigidity bar. this range can be seen by the purple color on the bar, with the rest of the bar being locked off unless the player changes their membrane type.
Cell walls add rigidity to your cell along with other buffs/debuffs. when you evolve a certain cell wall there will be a point on your rigidity bar that will be permanently locked. you wont be able to adjust your rigidity in anyway.
I havent thought of many status buffs/debuffs but here are some basic ones that have already been discussed:
Higher chemical weapon resistance
Higher Pilus weapon resistance
Less efficient absorbtion of compounds
Slower Movement speed
Higher rate of regeneration
The way I was thinking about it (and the way it was thought up on the dev wiki IIRC) was that a cell wall would not guard at all against agents, and if anything, would due to their slower movement speed even be really bad against it.
This would create a sort of ‘food pyramid’-esque mechanic, where there’d be stiff cells that would basically function as plants, which would not move because it would be too expensive energy-wise, but would also not need it (due to chloroplasts and the currents moving them around enough). To hunt them there would be ‘herbivores’, which would just dump some agents on the plants and then wait for a while for the plant to die out. (These would have both medium speed and medium energy consumption.) On top of that, there would then be the ‘carnivores’ which would have high speed (yes also high energy consumption) and use pilii to hunt herbivores and carnivores (And last of all there might be apex predators hunting the hunters)
I prefeer if membrane rigidity and cell wall type are sepparate things. We had this post on the forums about how temperature affects membrane fluidity, making in stiffer in cold environments and flexible in hot ones. I think modifying your membrane to adapt to temperature changes is a cool mechanic and if having a hard shell means your membrane is also rigid, tanky cells would be limited to only hot patches.