Could be a nice and unique platformer if you added a bit of polish.
Also here's an idea that this gave me, you could give them different mutations that you can choose from. So there's multiple ways of finishing a single level.
I'm definitely going to be updating it as time goes on. If you have any suggestions for different slime abilities, or specific areas of the game that I could polish up, feel free to let me know! I would love to hear your feedback.