Here is the full list of all 25 Larva Mortus achievements. It takes around 10-12 hours to unlock all of the achievements on Windows.
They give more lead to every shotgun blast.
This trophy added 4000 points to your score.
This trophy added 1000 points to your score.
This trophy added 2000 points to your score.
Doubles damage done by the sword.
Pistol bullets do +25% damage.
Adds +10 points of extra fire damage to crossbow bolts.
+10 points of extra damage to vampires.
Adds 10 bullets in every machine gun magazine.
This trophy added 10000 points to your score.
Duration of bonuses is +50% longer.
Silver bullets do +100% damage to werewolves.
Raises the probability that some item or bonus is dropped from an exterminated monster
+10 points of extra damage to demons.
This trophy added 3000 points to your score.
This trophy added 5000 points to your score.
Allows you to carry more ammunition for all weapons.