If you have access to the Namco Museum Arcade Beta (found through the HK and JP PlayStation Stores), you are able to unlock arcade games and shirts based on the games found in the beta. You can even put these arcade machines into your apartment, although if you want to play them, a user needs to have the beta installed on their machine.

Dig-Dug Arcade - Get 25% in score
Galaga Arcade - Get 25% in score
Pac-Man Arcade - Get 25% in score
Space Invaders Arcade - Get 25% in score
T-Shirt for each game - Get 50% in score