Damn! That's true! I wonder why would that be... O_o Copyright stuff?

http://www.explodingrabbit.com/videos/super-mario-bros-crossover-playing-my-own-game-3:

"The video has been taken down temporarily. It will be reposted sometime during the week of July 18th."

Very cool. The game has really fluid control. Haven't played a homemade Mario game which handles smoothly. Very good. You should create a sequel - Super Mario World Crossover, hint, hint!