News/Sonic 2 early prototype
Ok, this absolutely beats anything I've ever dumped and what I'm possibly ever going to dump.
For more screenshots and differences listed, see the topic on the forums.
Thanks to all the donators - Execbyte, Kat, Aurochs, LocalH, Orangefox, Erik JS, CheeseBacon, ScarredSun and Cyberdude. Wow, that's a long list. Thanks guys.
PS. The level select code is Up, Down, Down, Down, Down, Up, A+Start
Edit: there are lots of discussions about the game going on everywhere, on a lot of forums, but I think the best topic is Sonic 2 early prototype on the Sonic 2 Beta forums. Check it out for lots of differences detailed and explained.