need more challenges + animal idea

[wizardpope]

So I know I've made a previous thread about CO2 and terrariums etc being a problem. Well I've started a few colonies now and been somewhat successful. What I mean is that my stress levels were extremely low and my resources abundant. For example I got into the 30s in terms of cycles and was facing no hardship. I have 0% stress, plenty of algae, sufficient oxygen, etc. I didn't need to do more research or anything. I found myself deleting the colonies just so I could face a challenge again. I know I could have seen how long I would hold out but I had no desire to since it appeared I'd run relatively smoothly for many cycles to come. Idk what type of challenges can be thrown in but I would like to see more of a variety of them.

I'd like to suggest plants that convert co2 to oxygen, since that's how actual plants work. Maybe even having cool animals that have little trees on their backs that if you fully take care of them they produce oxygen everywhere they go. Maybe you feed them water or soil, something abundant enough to enjoy them but keep the oxygen production low so that it doesn't make things too easy.

[TheMetalMan]

I like it, maybe you could also assign certain dupes to take care of it. Then that Dupe is who the creature follows around.