Here is the full list of all 50 Middle-earth: Shadow of Mordor achievements worth 1,000 gamerscore.
Kill The Black Hand.
Kill The Tower.
Complete all Urfael Legend Missions.
Brand all 5 Warchiefs.
Acquire a level 25 Rune.
Capitalize on a Warchief's Fear.
After an uruk kills you to become a Captain, help him become a Warchief, then kill him.
Brand 5 Bodyguards of a Warchief, turning them against him in combat.
Save Lithariel's life.
Help a Captain survive a Recruitment Power Struggle, and then kill him and all his new recruits.
Perform an Execution on a flaming Berserker.
Start a Riot by commanding a Warchief to attack another Warchief.
Lift Lady Marwen's curse.
Brand a Captain while in combat.
Complete all Outcast Rescue Missions.
Poison a Captain at his own Feast.
Complete all Acharn Legend Missions.
Liberate 20 slaves in 300 seconds while riding a caragor.
Kill the Great White Graug.
Complete all Hunting Challenges.
Collect 100% of the Artifacts and listen to their memories.
Collect 100% of the Ithildin.
Complete all Azkâr Legend Missions.
Complete all Survivalist Challenges.
Activate all Forge Towers.
Kill The Hammer.
Issue a Death Threat, and then successfully kill the target.
Destroy the Monument Gate and topple the statue of Sauron.
Witness the creation of The Rings of Power.
Get Ratbag promoted to Warchief.
Kill all 5 Warchiefs before any uruk take their place.
Use Strike From Above while at least 60 feet above your target.
Collect 50% of the Ithildin.
Eliminate the bodyguards of two Warchiefs, then draw them out and kill them.
Successfully complete 4 Hunting Challenges.
Use the Detonate ability to burn 50 uruks.
Complete a Sword Mission and begin growing the legend of Urfael.
Make 20 uruks flee by dropping Morgai Fly nests.
Collect 25% of the Artifacts.
Attract caragors with bait 5 times.
Unlock 4 Dagger Rune slots.
Free 5 caragors from cages.
Complete a Bow Mission and begin growing the legend of Azkâr.
Unlock 3 Sword Rune slots.
Complete an Outcast Rescue Mission.
Successfully complete a Survivalist Challenge.
Discover some of the Wraith's past.
Unlock 2 Bow Rune slots.
Complete a Dagger Mission and begin growing the legend of Acharn.
Make an uruk yours.