I really liked the art and music, especially how your character got blue or red depending on which environment it was in!
I did also run into the issue with the walls, which would help a lot with the platforming feel. You could also add acceleration to the jump/side-to-side movement (but this is all stuff that obviously time limits make difficult).
Overall, a really cool concept to have different sections within the level that balanced your temperature (even if it was pretty difficult), and added a time pressure.