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