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