X comes with the same level editor that was used to make the main campaign. Wii, and five playable characters: Mario, Luigi, Toad, Princess Peach, and Link. Other new gameplay elements are the ability to fly the Koopa Clown Car that Bowser used in Super Mario World, plus the Billy Gun, which shoots Bullet Bills when picked up, Toothy, a Piranha Plant that the player can wield, the Propeller Block, a block that allows players to fly in New Super Mario Bros.

During a two-player game, the screen will split and recombine as the players separate and come together. Simultaneous two player co-op gameplay is one of the major features of this fangame. X is very similar to the games it was intended to emulate, most from Super Mario Bros.