The art and music are fantastic. The atmosphere of the game is also really cool. you did much more than I could with 3 colours.
On the other hand, I feel that there are many things you can improve:
Firstly, you should add a way to show whether the player still has the power up or not.
Secondly, I think it would be more fun if you made it that winning happens when the player clears all or most of the polution. because I can win the game by just clearing one which isn't very fun. Or maybe make so the player can continue playing after getting 300 points.
thirdly, the pits in the map that polution can get stuck in, I feel they don't really add a challenge instead they are just annoying.
I know I went a little hard with the criticism, but I just want you to improve. as I would love if someone did the same for me.