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