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.
Purchase a new multiplayer character.
Find all documents, relics and GPS caches.
Complete the game.
Fully mod and completely upgrade all weapons.
Complete all challenges.
Purchase all skills in all categories.
Complete all optional tombs.
Purchase all skills in one category.
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.
Kill 35 enemies with the pistol.
Kill 75 enemies with the rifle.
Loot 200 enemies.
Kill 40 enemies with the shotgun.
Kill 25 unaware enemies.
Kill 50 enemies with the bow.
Shoot a bundle of dynamite out of the air.
Incapacitate 25 enemies with dodge counter.
Shoot 10 enemies off zip lines.
Force an enemy to drop dynamite that kills two people when exploding.
Collect 5000 pieces of salvage.
Perform 50 headshot kills in the single player campaign.
Find 25% of GPS caches.
Collect 25% of all relics.
Perform 15 finishers.
Find 25% of all documents.
Kill and loot 10 small animals (rabbits, chickens, rats).
Kill and loot 10 flying animals (crows and gulls).
Complete one optional tomb.
Complete one challenge.
Kill and loot 10 large animals (deer, boar, wolves).
Survive 10 explosions in multiplayer.
In multiplayer, escape death 3 times by using the rope ascender.
Complete a match in all multiplayer modes.
Win a ranked match in every multiplayer mode.
Reach level 10 in multiplayer.
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.
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.