Nice to look at and fun to play. Neat idea and I love the use of color, shading, and effects. (Can't go wrong with glowy shrooms) c: Finished the game but didn't know how to reach some of the collectibles.
A few tips for controls would have been nice. And maybe having the walls you can jump climb on be slightly outlined or highlighted somehow would help. I didn't realize I could interact with them for a while. Even if they were a slightly different shade or something, that might be good enough.