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