Super Mario Bros. Dimensions (Complete 1.0.3)
Super Mario Bros. Dimensions is a 2D Mario fangame made in Game Maker 8.1 and powered with DrageZeeY Engine VII. The game uses 8-bit graphics and music. The game's twist is a "dimension-switching" gimmick that allows one to switch between two different variations of the level, at the press of a button. The game contains 66 levels in total across 9 different worlds.
The version of the game available here is Version 1.0.3.