Garry's mod just got an update with 15 Steam Achievements.
And here they are:
- Play Singleplayer - Play singleplayer at least once
- Play Multiplayer - Play multiplayer at least once
- Startup Millennium - Start Garry's Mod 1000 times
- Secret Phrase - Say the secret phrase
- Addict - You have wasted a year of your life playing Garry's Mod!
- Map Loader - Play 20 different maps
- Play Around - Play a gamemode that isn't sandbox
- Friendly - Play around with 10 friends
- are you the real garry? - Play on the same server as garry
- Marathon - Play on the same server map for 8 hours
- One Day - 24 hours of your life wasted
- One Week - One whole week of your life wasted
- One Month - One whole month of your life wasted
- Half Marathon - Play on the same server map for 4 hours
- Killed 1000 Baddies - Kill 1000 Baddies
Gary said that these are just the initial achievements, so expect more later on.