Hey that was cool. Loved the hypnotic audio and the art. I think a third button to rotate palette in the other direction would be a nice addition (although I appreciate the minimalism of two buttons). My main frustration was that it you couldn't tell which palette the hidden enemies and bullets were on. It would be cool if each enemy and bullet shape was exclusively on one palette so the player could learn to identify and quickly swap. Otherwise it feels like trial and error and kind of kills the flow.
No way am I getting 1500, this game is tough. ;-)