Here is the full list of all 21 Tower Tag achievements.
Take 10 headshots
Win a game
Finish the Tutorial
Play more than 24 hours
Log in for 7 days in a row
Win 5 games in a row
Win 10 games in a row
Achieve 50 sniper shots
Heal 20 players with less than 20% health
Heal 10.000 health points
Claim 100 tower
Teleport 1000 times
Receive the "Hottest Fire" award 10 times
Receive the "Coldest ice" award 10 times
Receive the "MVP" award 10 times
Play 50 matches
Play 100 matches
Play 200 matches
Reach level 10
Reach level 20
Reach level 30