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