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