Scratch

Check it out!  Here's a really fun simulation of a moto-cross motorcycle that you can make into a great game!

http://scratch.mit.edu/projects/Paddle2See/173249

It can drive up walls and even on the ceiling!  During jumps, it falls in whatever direction is underneath it's wheels at the current time.  If it goes out of control and runs into the edge of the screen, it is automatically reset to the center so it is very hard to break.  Have fun with it and I'd be happy to help anybody who wants to remix it into a full-fledged game.