This is a good start. Looking at the features laid out like this, I find myself pretty hesitant to try and tack on anything else in each update. It’s pretty substantial as is… But at least all of this wouldn’t be implemented all at once and more in intervals of 0.6.1 etc as usual.
Since I do not have a firm grasp of programming, I’ll try my best to lay features out in a “gameplay” point of view instead.
0.6:
Toxin rework:
With the upgrades system coming along around this time, I feel it’s a good period to throw in a rework to toxins as well. At the very least we could implement the various types of toxic delivery as elaborated in pacing and combat.
0.7:
Hydrogenase:
I was originally going to tack hydrogenosomes/hydrogenase to 0.6, but since they only have practical use in anerobic conditions, I figured they would be better off implemented during or after gas exchange. These are speculated to have evolved from mitochondria, therefore they might either fit well in the upgrades system or as a stand-alone part. Implementation should also be fairly simple as they operate very similarly to mitochondria, thus require no additional coding. I could probably even do it myself.
0.8:
Compound Toxicity/Environmental tolerance:
With the upgrades system implemented, and changing conditions present, 0.8 may be a good period to make those conditions matter more. It’s been a while since I last touched up on that topic, and looking back, it adds a ton of complexity. I propose the following;
Exposure to conditions you are unadjusted to adds a new passive ATP upkeep to your cell identical in function to osmoregulation; The idea being that moving outside of your cell’s comfort zone forces them to expend more energy maintaining their homeostasis. We might need to add a warning about this to patches, perhaps include a “habitability score” to the patch screen for quick reference. I’ll make a post elaborating on this at a later time.
Environmental Events:
With the implementation of changing conditions being completed in 0.7, I believe 0.8 is a good timeframe for the implementation of other events that might spontaneously change the conditions of a patch.
Events such as volcanic activity in any of the floor patches drastically increasing temperature and creating dangerous hotspots for a time, or atmospheric migration, which causes certain species to be swept up from far away surface patches, and dropped into other new patches via rain (Would this just be part of migrations?).
Other than that, I think the roadmap is good. I’m fairly confident I am forgetting a few things though, so I’ll edit this post if I remember.