@_abyss The goal is to beat New Super Mario Bros. Wii as quickly as possible. If it's not an official release of the game, it's not actually New Super Mario Bros. Wii, even if it's pretty close.

Adding on to what Josh said, not being an official release matters a lot (contrary to the initial statement about how it's not some boogeyman). There are many (many) games that only allow official releases. AFAIA, most popular wii speedgames don't allow emulator (for example emulator is banned in MKWii on src and in TTs).