Here is the full list of all 27 Gear Up achievements.
Destroy 20 enemies with the Grayhound (saws).
Destroy at least seven different opponents in a team game mode.
Destroy 10 enemies with the default starter cannon.
Drown in the water at least once.
Repair 30000 armor in lifetime.
Assist in capturing at least 20 conquest towers in a single round.
Win a TDM round overwhelmingly, with a ratio of 4:1 or higher.
Repair (1250) armor in one round of a team game mode.
Capture a conquest tower together with 3 or more teammates.
Back playing after more than one week of Gear Up absence.
Win 20 conquest rounds.
Win 20 deathmatch rounds.
Destroy 1500 enemies
Win 20 team deathmatch rounds.
Recieve 500 damage without being destroyed in a round.
10 kills in a row
Win a Conquest round overwhelmingly, with a ratio of 4:1 or higher.
6 kills in a row
Destroy 100 enemies
Destroy 75 enemies
Win 3 conquest rounds.
Destroy 50 enemies
Killed a deserting enemy
Destroy 25 enemies
4 kills in a row
3 kills in a row
2 kills in a row