I found the game quite enjoyable, the levels were great and fun. The art and the constantly changing background fits the game jam theme.
The movement mechanic is great and well executed. The addition of enemies added to the difficulty of the levels.
I would I argue that the "eject" button is part of Mr. Cools movement, because without it he wouldn't be able to change the direction of his movement, so technically there's two buttons.
Overall the game itself is really good and it perfectly fits the game jam.