Meet the GameShell: a programmable game console with a Linux embedded operating system that allows you to play classic games from Atari, NES, and other consoles. Cave Story and DOOM1 are included but more free games will be available in the future. C, Python, Lua, and LISP languages are supported, so you can create your own games and modes.
GameShell has 5 independent modules (screen, keypad, Clockwork Pi mainboard, stereo speaker, and battery) and can be put together easily. Expected to ship in April.