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 a zip-lining enemy player in multiplayer.
Kill 2 multiplayer enemies with a single explosive.
Complete all challenges.
Find all documents, relics and GPS caches.
Fully mod and completely upgrade all weapons.
Complete all optional tombs.
Find 75% of GPS caches.
Purchase all skills in all categories.
Incapacitate 25 enemies with dodge counter.
Win a ranked match in every multiplayer mode.
Complete a match in all multiplayer modes.
Purchase a new multiplayer character.
Kill 10 multiplayer enemies using your melee attack.
Collect 75% of all relics.
Find 75% of all documents.
Complete the game.
Fully mod and completely upgrade any weapon.
Purchase all skills in one category.
Kill and loot 10 flying animals (crows and gulls).
Complete all conversations with the Endurance crew.
Kill FeeFee the crab.
Collect 5000 pieces of salvage.
Kill 50 enemies with the bow.
Kill 25 unaware enemies.
Kill and loot 10 small animals (rabbits, chickens, rats).
Loot 200 enemies.
Kill 75 enemies with the rifle.
Kill 40 enemies with the shotgun.
Force an enemy to drop dynamite that kills two people when exploding.
Shoot 10 enemies off zip lines.
Find 25% of GPS caches.
Shoot a bundle of dynamite out of the air.
Collect 25% of all relics.
Catch a player in a snare trap in multiplayer.
Survive 10 explosions 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.
Complete one optional tomb.
Find 25% of all documents.
Rope pull 5 enemies off edges.
Perform 15 finishers.
Perform 50 headshot kills in the single player campaign.
Kill 35 enemies with the pistol.
Complete one challenge.
Kill and loot 10 large animals (deer, boar, wolves).
In multiplayer, escape death 3 times by using the rope ascender.
Kill 20 enemy players in multiplayer using a turret.