Bouncing around in this game was reaaally fun! The few times I made it become yellow felt so good, but I wish there were more situations it could happen! I think that this game would benefit a lot from doubling down on the speedrun factor, and allow people to bounce on any hard surface, because walking is much less fun than what you managed to make feel great - namely the bouncing!
I also thought that the footsteps were a bit too loud and repetitive, which is easy to solve by randomizing the pitch slightly! Or by indeed letting people bounce around more :b
All in all, I had a bunch of fun with this game, and can definitely see an eventual final product becoming really cool!