This game is amazing, well done! I normally dislike shoot'em up but I tried this one and is veeery addictive I am impressed! My score was 750 =) very happy with that!
My only complainment is that you should give more rewards, or limit the amount of colours you can use in the beginning so that the player that receives the new pallete, when a new level is reached, should feel rewarded! Only then you can switch colours based on the new pallete colours you got! If I could give an indicative of what I am talking about, please see the game "Gato roboto".
In any case, thank you very much for providing this game on the bundle! Amazing!