Oooh! I really like the concept of both you and the enemy changing depending on the tile! It's really cool!
I did not like having to use the weapon of the correct color to kill the enemy. The main reason is because I almost never got a chance to use the orange machine gun! Since the enemies are flying around at random, it's hard to predict where they will step next, and only the purple weapon has a range that lets you stay safe.
I would have personally liked it more if the enemies had similar patterns to yours (spread of bullets in orange, charged shot on green and long range shots on purple) and there was no color matching immunity.
That said, I really enjoyed the concept! Nice job!