Mods of iconic and classic video games are nothing new but this one seems to be quite a massive overhaul of the N64 Gem Super Mario 64. As the creator of the mod describes it: “This Game has 130 stars, 12 power-ups, many new bosses and a large variety of completely new levels. Over 4000 hours of work finally come together.”
Seems to be quite the expansive iteration of Mario 64 and you can learn more about this project on his YouTube Page.