Great art, the overall feeling of the game is great. The game is really hard right now and the change of control is hard to notice.
Maybe slowing the ennemies (and maybe increasing there speed each change of control) could help with the difficulty.
Also I would propose to remind the control directly on the border of the red planet and maybe make those controls blink 2-3 sec before they change, it would help the player to look at the new control and know when there is a change.
Overall a good game! Hope to play your next games :)