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