Here is the full list of all 24 The Mean Greens - there are Plastic Warfare achievements.
Play your first round
Sink in the sands of the Fish Tank
Die 100 times
Kill 100 enemies with the Bazooka
Kill 100 enemies with the Flamethrower
Kill 100 enemies with the Grenade
Kill 100 enemies with the Assault Rifle
Kill 100 enemies with the Shotgun
Kill 100 enemies with the Sniper Rifle
Kill 100 enemies
Deal 50,000 damage to the iceblocks in Deep Freeze
Make it all the way to the cup in Kitchen Run without taking any damage
Capture the enemy team's flag 100 times
Drown in Bathtub Bash 10 times
Land on the shark in Fishtank Frenzy
Hurdle 5 RC cars without getting hit on Toybox Assault
Run up or down every xylophone in Toybox Assault without dying
Don't sprint for an entire game
Play 20 rounds
Play on the Green team 100 times
Play on the Tan team 100 times
Drop below 20 health and regenerate 5 times without dying
Get hit by the RC cars on Toybox Assault 20 times
Capture an enemy flag and bring it back to your base without taking any damage in Fishtank Frenzy