This is a very original and elegant idea, especially when I realized you can control who moves with the color as well. I kinda want to make a clone now, so you should probably make more levels and publish it somewhere. It was never annoying, which is great for a platformer, probably because the controls are so smooth. My only nitpick is you can probably have a respawn animation where the zombies wait until you are finished instead of cutting to XX% left because it was rather jarring.