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.
Incapacitate 25 enemies with dodge counter.
Complete all conversations with the Endurance crew.
Rope pull 5 enemies off edges.
Win a ranked match in every multiplayer mode.
Kill 20 enemy players in multiplayer using a turret.
Revive a teammate in a multiplayer match.
Complete a match in all multiplayer modes.
Kill 10 multiplayer enemies using your melee attack.
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.
Catch a player in a snare trap in multiplayer.
Complete all challenges.
In multiplayer, escape death 3 times by using the rope ascender.
Reach level 10 in multiplayer.
Survive 10 explosions in multiplayer.
Find all documents, relics and GPS caches.
Complete the game.
Kill 40 enemies with the shotgun.
Fully mod and completely upgrade all weapons.
Complete all optional tombs.
Purchase all skills in all categories.
Find 75% of all documents.
Fully mod and completely upgrade any weapon.
Find 75% of GPS caches.
Collect 75% of all relics.
Kill FeeFee the crab.
Kill and loot 10 flying animals (crows and gulls).
Loot 200 enemies.
Kill 75 enemies with the rifle.
Shoot 10 enemies off zip lines.
Purchase all skills in one category.
Kill 35 enemies with the pistol.
Force an enemy to drop dynamite that kills two people when exploding.
Shoot a bundle of dynamite out of the air.
Collect 5000 pieces of salvage.
Find 25% of GPS caches.
Kill 50 enemies with the bow.
Perform 15 finishers.
Kill 25 unaware enemies.
Collect 25% of all relics.
Perform 50 headshot kills in the single player campaign.
Find 25% of all documents.
Complete one challenge.
Kill and loot 10 small animals (rabbits, chickens, rats).
Kill and loot 10 large animals (deer, boar, wolves).
Complete one optional tomb.