Full list of all 70 Gears of War: Judgment achievements worth 1,500 gamerscore. It takes around 50-60 hours to unlock all of the achievements in the base game.
The base game contains 50 achievements worth 1,000 Gamerscore, and there are 2 DLC packs containing 20 achievements worth 500 Gamerscore.
Played any section in 4 player Co-Op
Recovered all 48 COG Tags during the Campaign
Completed all Campaign Chapters on at least Hardcore difficulty
Attained 100 Stars on at least Hardcore Difficulty
Recovered 25 COG Tags during the Campaign
Recovered 10 COG Tags during the Campaign
Won 10 matches of Overrun
Achieved level 50 a third time and chose to re-up for another tour
Achieved level 50 a second time and chose to re-up for another tour
Won one match on every map in Overrun
Killed with all classes of Locust in Overrun
Killed with all classes of COG in Overrun or Survival
Won a match on every map in all Versus modes
Won one match on every map in Free For All
Achieved level 50 and chose to re-up for another tour of duty
Reached level 50
Reached level 40
Watched Aftermath teaser
Completed Aftermath
Earned 3 unique Ribbons in any section
Earned at least one Onyx medal
Reached level 30
Won one match on every map in Domination
Completed all Declassified missions
Won 10 rounds of Team Deathmatch
Equipped your first Medal
Won one match on every map in Team Deathmatch
Reached level 20
Completed all Campaign Chapters in Co-op
Completed all Campaign Chapters on at least Casual difficulty
Completed all Campaign Chapters on at least Normal difficulty
Completed Courthouse
Completed Downtown Halvo Bay
Completed Onyx Point
Attained 75 Stars on at least Normal Difficulty
Completed at least 20 Declassified missions
Completed Seahorse Hills
Won one match in Free For All, Team Deathmatch, and Domination
Reached level 10
Attained 50 Stars on at least Casual Difficulty
Unlocked Aftermath
Completed Halvo Bay Military Academy
Completed Museum Of Military Glory
Reached level 5
Completed your first Declassified mission
Complete all Campaign Chapters on Insane difficulty
Attain all Stars on Insane Difficulty
Earn the Onyx "War Supporter" medal
Complete all Declassified Missions on Insane difficulty
Complete wave 10 on all maps in Survival mode
Won a Team Death Match game with the entire team wearing the Car 13 Armor skin
Played 10 matches total on BloodDrive
Earned a killing spree with the Boomshield on Boneyard
Earned 50 Double ribbons with the Booshka on Terminal
Revive 100 total teammates on Terminal as a Medic
Get a Double while emerging as a Corpser
Kill 100 enemies with each Locust
Win Hardcore Survival on Terminal with 5 Soldiers
Earn the You’re It ribbon on Boneyard
Place first in Free For All in Boneyard 5 times
Earn the Tree House Predator ribbon on Ward
Destroy the generator in under 8 minutes on any DLC map
Get a multi-kill while playing as an enraged Rager on Ward
Finish wave 10 of Survival at the first e-hole on Ward on at least Normal difficulty
Score a flag cap on Streets, Rig, Gondola, Library, Lost City, Museum, and Checkout
Get a kill with each pickup weapon in FFA during a single game on the map Lost City
Kill the flag carrier a total of 20 times
Win a TDM, DOM, and BT match with your entire team wearing the UIR Armor skin
Score 5 flags in BT as Paduk
Win public/ranked game of Execution on Museum with all players using Gold character and weapon skins