The old version of Super Mario Bros. Crossover was too complicated with its fancy graphics and sound, so we ported it to Atari. Since Atari has less memory than Nintendo, we took out some of the characters. I think you’ll like this new version of SMBC much better. I know I do.
Play it here. (link removed)
Edit: This was an April Fools joke. You can still play the atari version by clicking the link above. The Atari skin will be included in the game in a future update.