howdy! i'm gonna leave a few little screenshots here that i hope are helpful for communicating feedback and maybe debugging. there is a chance i'm not sure what's going on so feel free to let me know if that's the case!
i was able to place different blocks inside other blocks (fungus & solar, building in a tree, etc).
in terms of the balanced values, i had the above spread (everything at 0 except for O2 at -2) for about ten plus days until my system eventually adjusted and then failed:
i think i had all values near ideal levels so everything was a'okay until the balance gave out, i was unsure though of what constituted a 'collapsed system' and what resulted in the 'game over' at the end. i think that communicating target levels more clearly and, in the event of a game over, reporting the reasons for it (i.e. "your CO2 was too high") would help the player a lot!
overall, very cool idea! i'm really envious on what you were able to accomplish in such a short time span. i would love to see how this looks post-jam with some more polish.