I was quite shocked to see that the character gets so fast lol The acceleration needs tuning, for sure. I didn't really see any reason to change the color of the bullet. Did different bullets have different abilities? If not then I think it'd be cool if they did :D  Also, I know that the game is called A lot of colors but it was quite hard to see because of that background.

Cool stuff, can be a lot cooler with a bit of tweaking :)