I'm talking about the Hackvision, a tiny (the size of a control pad) 8-bit video game console based on the Atmega 328. It is an open source project that allows you to write your own games using the Arduino TVout library.
From http://nootropicdesign.com/hackvision:
Hackvision is a simple, retro gaming platform based on Arduino technology that you can assemble and connect to your TV. You can write you own games and make your own controllers!