- A crouch button, which would probably be useless aside from maybe reducing your movement. Really I just want this to be implemented so I can crouch and then cuddle with the slimes.
Perhaps give the Tarr upgrades depending on what they were before they turned into Tarr. For example, a Tabby Phosphur Largo eating a Rock Plort when turned into a Tarr could move faster, jump like a Phosphur, and have spikes. If a pink slime has any part in the transformation (whether it be that it was part of the largo or the plort was pink), then it will always be a regular Tarr, no matter what the other components are.
Add coop sized walls to incinerators, so that it's less likely for poor slimes to randomly wander into them, while still small enough to throw some Tarr in there.
Add upgrades for ponds. This should be self explanatory. Things like walls, plort collectors, more water...
Downgrade the jetpack into a more of just hover in place instead of go up and then hover in place, or make it more like a glide.
EDIT: Can't forget, slow down the pacing a bit, whether it be by reducing how much Plorts give you or increasing the cost of things. Right now I feel like it only takes a few ingame weeks to do everything.
That's really all I can think of for now. If I think of anything else, I'll put it in here.