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