Play Sonic Advance 3 (prototype) Online

I recently got my hands on a prototype build of Sonic Advance 3 for the Game Boy Advance, an early version that never saw an official release. Developed by Dimps and published by Sega, this build gives a raw look at the development process during the GBA's peak, when 2D platformers were still a major draw. It's clearly unfinished, with placeholder assets and incomplete zones, but it's a fascinating glimpse into how the game evolved before hitting store shelves.

You control Sonic, Tails, or Knuckles, each paired with a partner character who provides unique movement abilities, like Tails carrying you for a short flight or Knuckles breaking certain walls. The goal is to race through multi-path stages, hunting down Chaos Emeralds while avoiding spikes and enemies. Signature mechanics include the partner-based team moves, which open up new routes, and the emphasis on high-speed platforming with pinball-like bumpers and loop-de-loops. The pacing is frantic, and the level design in this build can be unforgiving due to collision errors and missing checkpoints. Even with its rough edges, the sheer momentum and responsive controls make it hard to put down.