Here is the full list of all 30 Feral Fury achievements.
Complete Stage 5 with Rose the Red
Defeat The Corrupted with Rose the Red
Unlock all Secret Doors
Complete Stage 5 with The Traitor
Return the Missing Book
Open the Talismans Portal
Complete Stage 5 with a Panda Marine
Complete Normal Mode
Complete Stage 4 on Hard difficulty
Complete Easy Mode
Squash 20 lizards
Unlock 10 Upgrades
Complete Stage 3 on Normal difficulty
Close 10 Wishing Wells
Use 9 Syringe Rooms
Spend 30 Coins on Vending Machines
Complete Stage 2 on Normal difficulty
Complete an Entire Stage Without Taking Damage on Normal or Hard Difficulty
Send 10 Marines into Battle
Complete Stage 1 on Normal difficulty
Rob a store
Go Through a Teleporter
Complete Stage 5 with Admiral Pawgarr
Defeat The Corrupted with a Panda Marine
Defeat The Corrupted with Admiral Pawgarr
Defeat The Corrupted with The Traitor
Get 150 000 points in a Daily Run
Complete Curse Mode
Complete Feral Fighters with at least 9000 points