The Tower Challenge

That's a game that I and a friend started developing some time ago. It's not finished, but we want to get back to it someday.
I was responsible for the art, and Guilherme de Oliveira was the programmer.
The objective of the game is to climb the tower as the camera goes up. You must keep yourself in the screen and avoid all the obstacles. You can play it with up to 3 other players, so the last one in the screen is the winner!