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