So, this is a prototype build of Sonic Advance 3 for the GBA—basically an early, unfinished version of the game before the final release. It’s got that classic Sonic speed, but some of the levels feel a little rough around the edges, like they didn’t quite finish tweaking the physics or enemy placements yet.

You still get to team up Sonic with Tails or Knuckles (or Cream if you’re into that), but some of the combo moves don’t work as smoothly as they do in the final game. It’s kind of cool to see what got changed or polished later—like stumbling onto a secret dev room where everything’s half-built. If you’re a Sonic nerd, it’s a neat little time capsule.

Just don’t expect it to play as tight as the retail version. You’ll hit a few weird bugs, but that’s part of the charm.