Here is the full list of all 49 Animalistic achievements.
Complete 5 levels.
Complete 10 levels.
Beat the game.
Die for the first time.
Go Animalistic!
Kill one of each animal species.
Punch an exploding barrel into an enemy.
Destroy 5 collectables.
Destroy all collectables.
Kill an enemy with every gun.
Kill 100 animals.
Kill an enemy by throwing your gun at them.
Kill 5 enemies with one exploding barrel.
Kill 6 enemies at once while Animalistic.
Kill an enemy with your slide.
Die 10 times in one level.
Use a bomber to kill another animal.
Kill 10 enemies with one assault rifle.
Kill 2 enemies with one shotgun blast.
Kill a shield enemy with only your fists.
Complete a level in one minute.
Beat a level without killing an enemy.
Beat a level without taking any damage.
Beat a level only using fists.
Beat a level using every type of gun in the game.
Get shot 20 times in a level and beat it.
Complete a level with less than 10% of your health remaining.
Complete all levels without dying.
Beat all levels using only your fists.
Beat the game in under 45 minutes.
Receive every death message.
Punch through 100 doors.
Spend 30 minutes in one level.
Kill 1,000 animals.
Kill Carl the Croc.
Kill Thor the Boar.
Kill 50 flying animals.
Complete 15 levels
Defeat Animalistic's final boss
Find the first anonymous note
Solve one flying bat puzzle
Read 5 notes
Listen to 5 audio logs
Collect the Walkie Talkie
Collect the Biosample Gun
Collect the Vial
Begin the process of constructing the vaccine
Solve one password puzzle
Solve one torch puzzle