Dave Gnukem

Dave Gnukem is a 2D scrolling platform shooter. It is inspired by and similar to Duke Nukem 1, one of my all-time favourite games. It currently runs on Windows, Linux and BeOS.
Although this is by no means a finished game, it is playable. You can walk, jump, shoot baddies, collect stuff, die, teleport, open doors, use lifts, open boxes etc. There is also a level editor.