Here is the full list of all 49 Animalistic achievements.
Spend 30 minutes in one level.
Find the first anonymous note
Receive every death message.
Complete 10 levels.
Kill Carl the Croc.
Punch through 100 doors.
Kill one of each animal species.
Kill 10 enemies with one assault rifle.
Kill 2 enemies with one shotgun blast.
Destroy 5 collectables.
Die 10 times in one level.
Complete 5 levels.
Get shot 20 times in a level and beat it.
Use a bomber to kill another animal.
Kill 100 animals.
Kill an enemy with every gun.
Kill an enemy by throwing your gun at them.
Punch an exploding barrel into an enemy.
Kill 6 enemies at once while Animalistic.
Go Animalistic!
Die for the first time.
Beat a level only using fists.
Kill a shield enemy with only your fists.
Kill an enemy with your slide.
Beat the game.
Destroy all collectables.
Kill 5 enemies with one exploding barrel.
Complete a level in one minute.
Beat a level without killing an enemy.
Beat a level without taking any damage.
Beat a level using every type of gun in the game.
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.
Kill 1,000 animals.
Kill Thor the Boar.
Kill 50 flying animals.
Complete 15 levels
Defeat Animalistic's final boss
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