Here is the full list of all 50 Tomb Raider achievements. It takes around 40-50 hours to unlock all of the achievements on Windows.
Kill 35 enemies with the pistol.
Kill and loot 10 flying animals (crows and gulls).
Fully mod and completely upgrade all weapons.
Complete all challenges.
Find all documents, relics and GPS caches.
Complete the game.
Perform 15 finishers.
Purchase all skills in all categories.
Kill FeeFee the crab.
Fully mod and completely upgrade any weapon.
Complete all optional tombs.
Complete all conversations with the Endurance crew.
Find 75% of all documents.
Find 75% of GPS caches.
Collect 75% of all relics.
Loot 200 enemies.
Purchase all skills in one category.
Shoot 10 enemies off zip lines.
Collect 5000 pieces of salvage.
Kill 25 unaware enemies.
Collect 25% of all relics.
Find 25% of GPS caches.
Kill and loot 10 small animals (rabbits, chickens, rats).
Kill 50 enemies with the bow.
Perform 50 headshot kills in the single player campaign.
Find 25% of all documents.
Complete one optional tomb.
Complete one challenge.
Kill and loot 10 large animals (deer, boar, wolves).
Kill 75 enemies with the rifle.
Kill 40 enemies with the shotgun.
Force an enemy to drop dynamite that kills two people when exploding.
Rope pull 5 enemies off edges.
Incapacitate 25 enemies with dodge counter.
Shoot a bundle of dynamite out of the air.
Complete a match in all multiplayer modes.
Kill 20 enemy players in multiplayer using a turret.
Kill a zip-lining enemy player in multiplayer.
Catch a player in a snare trap in multiplayer.
Survive 10 explosions in multiplayer.
Revive a teammate in a multiplayer match.
Win a ranked match in every multiplayer mode.
In multiplayer, be the only player on your team that isn't dead or downed.
Kill 10 multiplayer enemies using your melee attack.
Kill 2 multiplayer enemies with a single explosive.
In multiplayer, escape death 3 times by using the rope ascender.
Purchase a new multiplayer character.
Reach level 10 in multiplayer.
Buy every upgrade and character in multiplayer.
Reach level 60 in multiplayer.