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