A new and amazing port of Super Mario has been release for the C64.
Despite having fewer sprites, fewer colors, fewer sound channels and a much slower processor (NES was 70% faster) the C64 port is astoundingly faithful and overcomes all of the aforementioned shortcoming.
It even makes new colors by flashing two colors together too fast for our eyes to detect!
Demo play on YouTube
You will get occasional slow downs on a stock C64, but not on a C128 at 2mhz or TurboChameleon. It also supports twin SIDS for full sound channels.