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