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