Simple controls which for phone must be great. 4 level which were increasingly difficult to beat. A little bug I found was, that when your mouse if far away from the screen e.g. on a neighboring screen more force is applied to the cube. This exploit could be use to just stick to a wall and slowly glide down :D.
I feel the hit boxes could have been more forgiving. Furthermore longer levels with average difficulty would have been great too.
All in all a complete experience which was fun to play.