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