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