This is at the brilliant work by ZeroPaige that Nintendo doesn’t want you to have: a seven year effort to bring Super Mario Bros. to the Commodore 64. Those of you familiar with the C64’s architecture will respect the mastery of 6502 and VIC-II required to make this happen (even in light of the fantastic Great Giana Sisters).
The file is here, and will remain here as long as possible regardless of any takedown requests from Nintendo.
Mecha-Mania Blog 