Here is the full list of all 50 X-Men Origins: Wolverine achievements worth 1,000 gamerscore.
Beat the game on Hard Difficulty
Found all Dog Tags in the game
Raised All Combat Reflexes to Master Level
Maxed out all upgrades
Killed 2000 enemies
Killed 25 enemies with a reflected projectile
Raised One Combat Reflex to Master Level
Flew through the O ring in the Sentinel Boss Battle
Killed 200 enemies with Claw Spin
You feel cold as you examine the skeleton and read the name "Arthas" etched into the nearby sword
Destroyed all objects in the grocery store fight with Fred Dukes (The Blob)
Defeated Weapon 11 (Deadpool)
Completed the Jungle Mission
Killed 200 enemies in Feral Sense
Light 20 enemies on fire
Killed 150 enemies while in Berserker mode
Defeated Remy LeBeau (Gambit)
Defeated Fred Dukes (The Blob)
Defeated the Sentinel Mark I
Dismembered 100 enemies
Killed 50 enemies while in Berserker mode
Found 1/2 of all Dog Tags in the game
Raised one Mutagen to level 3
Got 6 enemies airborne at once
You found the cake, yummy!
Performed a Wolverine to Wolverine Lunge
Defeated David Nord (Agent Zero)
Fought 4 W.E.N.D.I.G.0 prototypes at the same time and defeated them at Alkali lake.
Lunged to 250 enemies
Killed 25 Ghosts with their own weapon
Killed 30 enemies using objects in the environment
Killed 500 enemies
Killed 10 enemies by throwing them off high areas
Killed 6 enemies with a single attack
Escapes from Weapon X
Performed 10 Air Grabs
Lunged to 100 enemies
Killed 1 enemy with a reflected projectile
Quick Killed 20 enemies
Killed 10 enemies using objects in the environment
Quick Killed 3 enemies in a row
Quick Killed 1 enemy
Lunged to a W.E.N.D.I.G.0 prototype's back
Performed 25 Counter moves
Defeated Victor Creed (Sabretooth)
Impaled Victor Creed outside the Bar
Lunged to 25 enemies
Killed 100 enemies
You found a mysterious hatch!
Performed 1 Counter move