Es gibt auch ein Freeware Mario Game, was von fans gemacht wurde.
Mario Blue Twilight DX
Die Level sollten dir eg. gefallen.

Natürlich gibts auch illegale Roms, viele sind aber auch legal.
Habe mir auch mal so ein pack runtergeladen, Nintendo 64 Emulator mit Gex - Enter the Gecko und Gex³ - Deep cover Gecko

Auf der seite standen auch Games zur "verfügung", das waren eig. nur Pics, da stand auch das die Roms nicht legal als freeware zu beschaffen sind, alle roms waren auf der site legal.

Can I Download a Nintendo ROM from the Internet if I Already Own the Authentic Game?

There is a good deal of misinformation on the Internet regarding the backup/archival copy exception. It is not a "second copy" rule and is often mistakenly cited for the proposition that if you have one lawful copy of a copyrighted work, you are entitled to have a second copy of the copyrighted work even if that second copy is an infringing copy. The backup/archival copy exception is a very narrow limitation relating to a copy being made by the rightful owner of an authentic game to ensure he or she has one in the event of damage or destruction of the authentic. Therefore, whether you have an authentic game or not, or whether you have possession of a Nintendo ROM for a limited amount of time, i.e. 24 hours, it is illegal to download and play a Nintendo ROM from the Internet.