While the V2.2.2 version of the "Plus" edition is the one most commonly found online, it's based on a long history of updates. The original hack has gone through several numbered iterations. For example, patch notes for the base Sonic Edition included a host of improvements that are likely present in the V2.2.2 "Plus" build:

For those interested in experiencing this unique blend of Mario and Sonic, playing the Mario 64 Sonic Edition Plus V2.2.2 Rom requires a few steps:

Sonic features a much faster base walking and running speed, allowing him to sprint up steep slopes that would typically require careful climbing.

The hallmark of this modification is the radical shift in movement and physics. The developers, Thodds and Gamebun, meticulously implemented several of Sonic’s signature abilities: Momentum-Based Speed:

Here is the unavoidable criticism of Sonic Edition Plus V2.2.2 : The levels were not built for this.

The V2.2.2 update introduces several technical and mechanical enhancements that set it apart from early iterations of the hack:

Version 2.2.2 is highly optimized compared to its predecessors. Earlier versions frequently suffered from crashes during Bowser boss fights or heavy frame drops in water levels like Dire, Dire Docks .

You cannot legally download a pre-patched ROM. To play it: