Here is the full list of all 46 Trash Squad achievements.
Collect seeds playing as Mud Thing.
Kill 40 mini bosses.
Kill 5000 monsters.
Destroy 5000 walls.
Kill 50 bosses.
Complete the game in Nightmare mode.
Open 50 chests.
Kill 25 mini bosses.
Destroy 600 elements not including walls.
Kill 30 bosses.
Hire 15 mercenaries.
Kill 25 bosses.
Unlock 8 characters.
Destroy 400 environment elements except for walls.
Open 30 chests.
Unlock 3 character skins.
Complete the game in Normal mode.
Kill 10 mini bosses.
Collect 2000 armour units in total.
Destroy 300 elements not including walls.
Complete the game in Cannonade mode.
Open 20 chests.
Kill 1500 monsters.
Unlock 4 characters.
Destroy 2500 walls.
Complete the game in Horde mode.
Hire 5 mercenaries.
Kill 1000 monsters.
Kill a chicken in the Composter.
Kill 5 bosses.
Destroy 600 walls.
Unlock 1 character.
Destroy 500 walls.
Open 5 chests.
Unlock 7 character skins.
Unlock 10 character skins.
Unlock 15 character skins.
Unlock 3 skins for a single character.
Unlock 3 skins for each of 5 characters.
Unlock 3 skins for each of 10 characters.
Kill 10000 monsters.
Complete the game in Elite mode.
Destroy 1200 elements not including walls.
Collect robot parts playing as Welder.
Hire 35 mercenaries.
Achieve rank 2.