This is a really simple game: You push boxes by walking into them. You can't push more than one box at once. Your task is to put all boxes to spots marked by marbles. A box gets coloured red when it stands on a marked spot. And since the game is 3D, you can move all 6 directions: left, right, forward, backward, up, down.
There are 7 levels so far and it is possible to add more. Feel free to contribute some ;)