About
Super Mario Bros. 3 is a 1988 Nintendo Entertainment System platform game developed by Nintendo under Shigeru Miyamoto and Takashi Tezuka, first released in Japan in 1988 and later in North America and Europe. 3Mix is a full-scale ROM hack of Super Mario Bros. 3, assembled with the NESASM assembler and requiring the original SMB3 ROM to build; it includes optional support files for the NoDice level editor and the MusConv music-conversion tool.
How it differs from the original
By its own description, the hack borrows gameplay concepts and ideas from many games released after the original Super Mario Bros. 3, though it doesn't specify which ones.
Getting started
Assemble the hack's source with the NESASM assembler against your own Super Mario Bros. 3 ROM to produce a playable ROM file.