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