Full list of all 15 Marathon: Durandal achievements worth 250 gamerscore.
The base game contains 12 achievements worth 200 Gamerscore, and there are 2 DLC packs containing 3 achievements worth 50 Gamerscore.
Get seven fist kills in the game.
Venture into the Citadel and learn the secrets of the S'pht.
Complete the Single player game in any difficulty.
Get 20 Tozt-7 kills in a Multiplayer game.
Win a Multiplayer game.
Kill an invincible opponent with the Fusion Pistol in a Multiplayer game.
Get 20 Rocket Launcher kills in a Multiplayer game.
Find the Assault Rifle in a Single player or Co-Op Game, it will let you kill more Pfhor.
The secret of 2401 lies within.
I give no secrets.
You want to join the 7th Column?
Kill a Juggernaut in Survival and live to tell the tale.
Outscore all the other players (at least 3) combined in a KOTH or KTMWTB game.
Win a multiplayer game with at least 4 players in every map in the Total Carnage Netmap Pack.