Fun game! The movement's good and the background is nice. I just like to mention some things about the game which I thought could be improved on.
The little cube on the marshmallow looks a bit odd, although I understand that's to make sure the player knows which side is the front.
Some sound effects and music would add a lot to the game.
The main menu doesn't adapt to fullscreen, it would look a lot nicer if it did.
You have to jump onto the wooden ramp at the beginning of the game, it would feel better if you could just walk up it.
Overall, nice work!