Classic gamers may remember the awesome game "Great Giana Sisters", the awesome platformer for the C64 and Amiga that was a little TOO close to Super Mario Brothers, and ended up getting themselves sued and losing to the big N.
The sisters are back.
http://www.gianas-return.de/index.html
It's in beta and while it was originally planned to be a GP32 specific game, it's already been ported to the Dreamcast. When the game reaches it's final release state, a PC version will also be released.
Free 2D for you and me. Go check it out!