I enjoy the idea behind it! A battle puzzler where you need to change colors to combat against specific characters without taking damage. I had a harder time finishing certain levels because of some bugs in movement, but the core idea is there.
I would suggest significantly turning down the saturation on the background colors, as it's super glaring to go from cyan to straight harsh bright red, then harsh bright red. Also, the sword attack feels like it could be improved. It's not clear why you can't attack enemies while on top of them, for example.