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