Here is the full list of all 19 RedEx achievements.
Buy Berrett M82 at the menu store
Buy every weapon at the menu store
Unlock Hidden
Buy your first spy computer
Defeat Helicopter Boss for the first time
Unlock Veteran
Buy 3 turrets at the same time
Defeat Pickup Boss for the first time
Scratch up 100 Silver coins throughout one battle
Use toolbox for the first time
Buy your first weapon at the menu store
Place signal receiver for the first time
Your turret is destroyed by enemies. I'm sorry
Buy your first supply in the terminal
Kill Cyborg Boss in the Labs for the first time
Defeat every Boss in game
Fully upgrade your skills
You've got every achievement! Thanks for playing!
Destroy your Tesla Tower