Here is the full list of all 21 Lambda Wars Beta achievements.
Build 20 Striders.
Win a Combine vs Rebels game in a 4v4 match of Annihilation or Destroy HQ.
Win an Annihilation game.
Complete the Tutorial level.
Complete the mission for Radio Tower.
Complete the mission for Abandoned.
Complete the mission for Valley.
Defeat 20 enemies in Annihilation games.
Defeat 100 enemies in Annihilation games.
Win 20 Destroy HQ matches.
Win 100 Destroy HQ matches.
Kill Dog.
Make your 50 very own zombies!
Kill 5 different units with one combine ball.
Kill 300 units with Suppression Device in Annihilation or Destroy HQ game mode.
Blow up 100 enemy buildings with Saboteurs in Destroy HQ or Annihilation mode.
Build 20 Dogs.
Reprogram a Floor Turret with a Saboteur and kill an enemy unit with it.
As Rebels, kill 10 units with one grenade.
Collect 50 Partisans together in Annihilation or Destroy HQ mode.
Complete the mission for Waste.