Here is the full list of all 32 Tanknarok achievements worth 1,000 gamerscore. It takes around 2-3 hours to unlock all of the achievements on Xbox One.
You played TANKNAROK for the first time! Great!
Play 100 local matches
Destroy two enemies with one shot
Bounce 500 times on bumpers
Break 100 dungeon urns
Break Frosty the snowtank
Break the outhouse
Destroy 500 tanks
Kill all other tanks in a round with four players
Honk 1000 times
Kill three tanks in a row during a single match without dying
Kill four tanks in a row during a single match without dying
Kill five tanks in a row during a single match without dying
Kill six tanks in a row during a single match without dying
Kill 20 tanks using krokogators
Kill 20 tanks using the boomstick
Kill 20 tanks using the minigun
Kill 50 tanks using the laser gun
In a 4-player game, kill all other tanks in less than three seconds
Kill 3 other players using a single powerup
Kill an enemy tank from the grave with the Controlled Missile
Kill the tank that killed you last
Kill your own tank with your own weapon
Play a match in local mode with 4 players
Play in all themes
Stun 100 drones
Survive a level with full health
Win 10 matches online
Win a match 5-0
Win a round without firing your cannon
Win a round without picking up any powerups
Unlock all TANKNAROK achievements