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.
Earned the Onyx "War Supporter" medal
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
Completed wave 10 on all maps in Survival mode
Achieved level 50 and chose to re-up for another tour of duty
Reached level 50
Won 10 matches of Overrun
Completed all Campaign Chapters on at least Hardcore difficulty
Completed all Campaign Chapters on Insane difficulty
Attained all Stars on Insane Difficulty
Completed all Declassified Missions on Insane difficulty
Attained 100 Stars on at least Hardcore Difficulty
Won 10 rounds of Team Deathmatch
Earned at least one Onyx medal
Reached level 40
Recovered all 48 COG Tags during the Campaign
Reached level 30
Completed Aftermath
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
Completed Courthouse
Completed all Campaign Chapters on at least Casual difficulty
Completed all Campaign Chapters on at least Normal difficulty
Completed all Campaign Chapters in Co-op
Completed all Declassified missions
Completed Downtown Halvo Bay
Recovered 25 COG Tags during the Campaign
Earned 3 unique Ribbons in any section
Completed Onyx Point
Attained 75 Stars on at least Normal Difficulty
Played any section in 4 player Co-Op
Won one match in Free For All, Team Deathmatch, and Domination
Completed Seahorse Hills
Completed at least 20 Declassified missions
Attained 50 Stars on at least Casual Difficulty
Recovered 10 COG Tags during the Campaign
Completed Halvo Bay Military Academy
Unlocked Aftermath
Reached level 20
Completed Museum Of Military Glory
Completed your first Declassified mission
Won one match on every map in Domination
Equipped your first Medal
Won one match on every map in Team Deathmatch
Reached level 10
Watched Aftermath teaser
Reached level 5
Got a Double while emerging as a Corpser
Placed first in Free For All in Boneyard 5 times
Played 10 matches total on BloodDrive
Earned 50 Double ribbons with the Booshka on Terminal
Revived 100 total teammates on Terminal as a Medic
Earned a killing spree with the Boomshield on Boneyard
Earned the You’re It ribbon on Boneyard
Won a Team Death Match game with the entire team wearing the Car 13 Armor skin
Won Hardcore Survival on Terminal with 5 Soldiers
Killed 100 enemies with each Locust
Won public/ranked game of Execution on Museum with all players using Gold character and weapon skins
Finished wave 10 of Survival at the first e-hole on Ward on at least Normal difficulty
Won a TDM, DOM, and BT match with your entire team wearing the UIR Armor skin
Destroyed the generator in under 8 minutes on any DLC map
Got a multi-kill while playing as an enraged Rager on Ward
Earned the Tree House Predator ribbon on Ward
Scored a flag cap on Streets, Rig, Gondola, Library, Lost City, Museum, and Checkout
Killed the flag carrier a total of 20 times
Got a kill with each pickup weapon in FFA during a single game on the map Lost City
Scored 5 flags in BT as Paduk