The device is very simple, you slide in the iPhone (most models are supported) and load the app you want to play (several, free in the app store under 'Arcadie')
Right now there's pong, Space invaders and Asteroids. More games are coming probably this month: Tetris, another version of space invaders and Planet Defender, a sidescrolling space shooter. More apps will be coming in the near future (i'm assuming)
For such a small price it's a nice addition for any geek, and it even looks cool just standing there on your desk. The buttons are pretty good and the arcade stick works quite nice. It works without bluetooth or other connections and doesn't need power it uses the iPhone connector to connect to the Arcadie. I bought it at the computergame museum in Berlin, Germany and i was pleasantly surprised by how fun it actually was to play with.