Full list of all 56 Game Room achievements worth 1,000 gamerscore. It takes around 60-80 hours to unlock all of the achievements on Xbox 360.
Reached Level 14
Won 20 Medals of each type
Reached Level 11
Won 48 Medals
Won 45 Medals
Won 42 Medals
Won 39 Medals
Won 36 Medals
Reached Level 8
Won 10 Point Buster Medals
Won 10 Medals of each type
Won 33 Medals
Won 10 Time Spender Medals
Won 30 Medals
Won 27 Medals
Won 10 Survivalist Medals
Won 24 Medals
Won 21 Medals
Reached Level 5
Won 18 Medals
Themed an entire arcade with unique Themes
Won 5 Point Buster Medals
Won 15 Medals
Won 5 Survivalist Medals
Won 5 Time Spender Medals
Won 12 Medals
Spent 36 hours total playing games in your arcade
Spent 24 Hours in your arcade playing games
Spent 16 hours in your arcade playing games
Spent 8 hours in your arcade playing games
Won 20 Challenges!
Won 10 Challenges!
Won 9 Medals
Played a single game for 1 hour continuously
Spent 4 hours in your arcade playing games
Won a Challenge!
Reached Level 2
Played a Friend's Game Cabinet
Won 6 Medals
Won 2 Medals of each type (2x Point Buster, 2x Survivalist, 2x Time Spender)
Visited a Friend's arcade
Won 3 Medals
Won a Medal of each type (Point Buster, Survivalist, Time Spender)
Visited the Showcase Arcade
Activated 1 Mascot in your arcade
Placed 5 unique Themes in your arcade
Filled a Room in your arcade
Placed 5 arcade Decorations in your arcade
Sent a Challenge!
Beaten your own High Score in a game, while looking cool!
Won your first Medal!
Placed a Theme in your arcade
Placed 1 Decoration in your arcade
Placed a Game Cabinet in your arcade
Reach Level 17
Reach Level 20