Here is the full list of all 49 How to Survive 2 achievements.
Finish 15 co-operative quests (local or online).
Help an ally in trouble 30 times.
Kill 10 infected animals of each species.
Meet every character in the game.
Equip a pet for the first time.
Finish Kovac's first challenge in co-operative mode (local or online).
Give an ally an item for the first time.
Reach the maximum level with your character.
Have the camp at maximum level.
Finish every quest.
Finish your first co-operative quest (local or online).
Successfully complete all of the elite quests.
Upgrade 10 weapons with modules.
Hit a car under alarm with a trash can.
Kill 100 infected with traps.
Kill 50 nocturnal infected.
Kill 5,000 enemies (of all types).
Kill 100 infected with silver bullets.
Kill 100 infected with flint-tipped fletched ammunition.
Kill at least 2 infected with one arrow or crossbow bolt.
Prepare a first potion.
Finish each of the game's festive quests.
Kill 10 infected with a Bomber explosion.
Wear the Jester's hat for the first time.
Pick at least one of every type of plant.
Join a public camp for the first time.
Upgrade a weapon with modules for the first time.
Kill 1,000 infected humans.
Pick 20 locks.
Finish Kovac's first challenge while keeping the pylon intact.
Kill 500 infected with a critical shot.
Pick a lock for the first time.
Customize your survivor for the first time.
Enter Kovac's bunker for the first time.
Kill 2 or more enemies at the same time with a melee weapon.
Kill an infected with a charged attack for the first time.
Successfully complete half of Kovac's challenges while keeping the pylon intact.
Successfully complete all of Kovac's challenges while keeping the pylon intact.
Kill 50 infected during a last stand.
Have all "Survival" skills at the maximum level.
Have all "Weapon" skills at the maximum level.
Have all "Stamina" skills at the maximum level.
Have all "Special abilities" skills at the maximum level.
Have all "In Danger" skills at maximum level.
Cook every type of recipe.
Prepare every type of potion.
Make every type of armor.
Make every type of weapon.
Drink 50 potions.