Indiegogo campaign to fund production of a simple stripped-down handheld console which is designed to easily create your own games (and can connect to upto 128 other devices) - video embedded below:
Gamebuino is a retro portable game console project based on Arduino. It allows you to make your own games, and even more.
It is designed so you can easily get started with your game, yet it is capable enough to make fully-featured 8-bit games and other badass projects. The library allows you to start programming your game in minutes, and the console is shipped ready to run, yet customizable thanks to the extension ports which allow you to add modules (like an accelerometer or wireless communication), or to connect several Gamebuino consoles to play in multiplayer with your mates.