The proof of concept game.

Platforming here is excellent and there are some especially tricky and difficult parts. It takes a minute to get how the momentum works but once you get it down it feels really good to play. Of course the music is quite good and even though it's an early Genesis title there's some excellent music here.

The only downside of this game is that the levels are a little too long. This game makes you really grateful that they dropped the 3 act structure in Sonic 2. There's a lot of set pieces that are copy/pasted into the level at random so at times it feels like you've somehow looped back around.