Sonic 2 Beta ROM vs. Final ROM - Metropolis Zone

Left: beta version, Right: final version

Beta version has metal crusher things, final version has the rotating mesh tunnel.

The steam-spring doesn't throw Sonic high enough, so you can't progress any further.

Left: beta version, Right: final version

Lava doesn't hurt you, different layout, and the moving platforms appear in front of the lava. The background is (partly) a different colour.

Weird parallelogram thing that crushes Sonic.