Here is the full list of all 12 Geometry Wars: Retro Evolved² achievements worth 200 gamerscore.
2, 4, 11, 15, 17, 18 and 19.
Reach the end of sequence.
Perform the Wax On achievement twice in a single game, don't forget to breathe.
Destroy 75 enemies in a game of Deadline using bullets bounced off of gates.
Activate 30 zones in King without firing a shot, or destroying any enemies.
Dodge 8 lines of enemies in Waves without firing a shot, or destroying any enemies.
Score 1,000 points in Waves without collecting any geoms.
Score at least 1,000,000 points in all single player modes.
Rub your ship along all four arena walls in Pacifism.
Unlock all game modes.
Chain together 5 gates in 5 seconds. Crossing at least one gate every second.
Collect 500 geoms in a single game.