I really like the presentation and feel of this game. But I also had the jump problem (even with the base slime). It really became a problem when I was trying to climb up the tree with ravens, as a missed jump and I would fall even lower. There was no pattern I could discern as to when it did/didn't work. :/
Music was cool, and the rest of the audio good too. I was enjoying the combining mechanic and how different slimes behaved when I got to those points. Congrats on the submission!