Very nice
So I just finished the game, and I loved everything about it. I can't wait for the sequel. By the way, are you ever planning on adding new colors for a whole new level of difficulty? Some things off the top of my head were:
Purple = Psychic powers
Orange = Long range shooting maybe?
Green = Defensive stuff? Maybe putting up walls or something
Black = (I think he should eventually utilize his enemies powers) Mind control or divination? Taking control of objects or enemies.
I see soooooo much potential with this game.
Just one thing though, your boss fights could use a lot of work :( But I think if you more colors and powers the boss fights could be pretty challenging.