Full list of all 78 Gears of War 2 (JP) achievements worth 1,750 gamerscore. It takes around 300-500 hours to unlock all of the achievements on Xbox 360.
Reached level 50 in multiplayer exeprience
Reached level 45 in multiplayer exeprience
Reached level 40 in multiplayer exeprience
Reached level 35 in multiplayer exeprience
Reached level 30 in multiplayer exeprience
Team survived all 50 Horde waves
Won 10 rounds of Guardian as the leader (public party)
Captured 10 meatflags (public party)
Won 3 matches of King of the Hill (public party)
Won 3 matches of Wingman (public party)
Reached level 25 in multiplayer exeprience
Made it through "Road to Ruin" with nothing but vengeance on your mind
Made it through "Road to Ruin" with a friend
Completed all campaign acts on Normal Difficulty
Completed all campaign acts on Hardcore Difficulty
Completed all campaign acts on Insane Difficulty
Recovered all 41 collectibles
Defeated the Lambent Brumak
Completed all acts in Co-op on any difficulty
Completed all campaign acts on Casual Difficulty
Captured a Brumak
Successfully defended COG headquarters
Defeated Skorge and his Hydra
Found the Locust queen
Activated Jack as homing beacon in Nexus
Found Maria
Defeated the Leviathan
Arrived safely at Mount Kadar Stranded camp
Discovered the location of the Locust queen
Performed a chainsaw multiple bypass
Killed 30 enemies raining down death from the sky
Killed an enemy with every weapon
Recovered 20 of 41 collectibles
Freed Baird from capture
Completed 10 chapters in Co-op on any difficulty
Watched Ilima sink
Seen the sights with Betty
Bashed 30 Tickers
Escorted Betty to Landown
Successfully defended the hospital
Recovered 5 of 41 collectibles
Completed 1 chapter in Co-op on any difficulty
Showed Carmine the ropes
Reached level 20 in multiplayer exeprience
Got up close and personal with the Boomshield
Reached level 15 in multiplayer exeprience
Torched 30 enemies
Killed 30 enemies with your Mulcher turret
Team survived 10 Horde waves
Effectively used grenade mines
Reached level 12 in multiplayer exeprience
Reached level 10 in multiplayer exeprience
Reached level 8 in multiplayer exeprience
Mastered the ways of the Active Reload
Reached level 5 in multiplayer exeprience
Win 10 chainsaw duels (any mode)
Use a meatshield to save your life 10 times (any mode)
Perform all 11 unique executions on a downed enemy
Kill 100,000 enemies (any mode)
Successfully complete the 5 lessons of multiplayer Training Grounds
Kill 10 enemies with a grenade while down but not out (any mode)
Play 1999 rounds of multiplayer (any mode)
Win a multiplayer match on each of the 29 shipped maps (any mode)
Complete waves 1 through 10 in Horde on all 29 shipping maps (any difficulty)
Complete waves 1 through 50 in Horde on all 29 shipping maps (any difficulty)
Play a multiplayer match on all 29 shipping maps
Earn enough multiplayer experience to reach level 55 (Horde or Public only)
Without being detected, complete the "Road to Ruin" deleted scene after choosing the stealth option
Earn enough multiplayer experience to reach level 60 (Horde or Public only)
Earn enough multiplayer experience to reach level 65 (Horde or Public only)
Earn enough multiplayer experience to reach level 70 (Horde or Public only)
Earn enough multiplayer experience to reach level 75 (Horde or Public only)
Earn enough multiplayer experience to reach level 80 (Horde or Public only)
Earn enough multiplayer experience to reach level 85 (Horde or Public only)
Earn enough multiplayer experience to reach level 90 (Horde or Public only)
Earn enough multiplayer experience to reach level 95 (Horde or Public only)
Earn enough multiplayer experience to reach level 100 (Horde or Public only)
Kill 25 Bloodmounts with a Scorcher while playing Horde (any difficulty)