ACHIEVEMENT - HOW TO UNLOCK
Battle-hardened - Complete all single player levels 1-5.
Elite Unit - Complete all single player levels 1-5 on Elite difficulty.
Exterminator - Kill 1000 aliens in single player.
Frag-master - Kill 10 aliens with one frag grenade.
Hidden Treasure - Find all secret collectibles.
Immobilised - Stun 10 aliens with one stun grenade.
Meat Grinder - Kill 250 aliens on any multiplayer Survivor level.
More Speed, Less Haste - Complete 'Vengeance' single player level on Veteran difficulty in 17 minutes or less.
Seasoned Squaddie - Complete any multiplayer level.
Survivor - Stay alive for 8 minutes on any single player Survivor level.
Tank - Take 500 damage on 'Determination' single player mission without dying.
The Informed - Collect all the logs throughout the game.
Time to Party - Complete 3 Co-op Assault multiplayer games.