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.
Catch a player in a snare trap in multiplayer.
In multiplayer, be the only player on your team that isn't dead or downed.
Find all documents, relics and GPS caches.
Complete the game.
Fully mod and completely upgrade all weapons.
Purchase all skills in all categories.
Incapacitate 25 enemies with dodge counter.
Force an enemy to drop dynamite that kills two people when exploding.
Complete all challenges.
Complete all optional tombs.
Complete all conversations with the Endurance crew.
Find 75% of all documents.
Purchase all skills in one category.
Collect 75% of all relics.
Fully mod and completely upgrade any weapon.
Find 75% of GPS caches.
Rope pull 5 enemies off edges.
Kill FeeFee the crab.
Kill 75 enemies with the rifle.
Kill 40 enemies with the shotgun.
Kill and loot 10 flying animals (crows and gulls).
Loot 200 enemies.
Shoot 10 enemies off zip lines.
Kill 35 enemies with the pistol.
Shoot a bundle of dynamite out of the air.
Kill 25 unaware enemies.
Collect 5000 pieces of salvage.
Kill 50 enemies with the bow.
Perform 15 finishers.
Kill and loot 10 small animals (rabbits, chickens, rats).
Find 25% of GPS caches.
Complete one optional tomb.
Collect 25% of all relics.
Perform 50 headshot kills in the single player campaign.
Find 25% of all documents.
Complete one challenge.
Kill and loot 10 large animals (deer, boar, wolves).
Complete a match in all multiplayer modes.
Kill 20 enemy players in multiplayer using a turret.
Kill a zip-lining enemy player in multiplayer.
Survive 10 explosions in multiplayer.
Revive a teammate in a multiplayer match.
Win a ranked match in every multiplayer mode.
Kill 10 multiplayer enemies using your melee attack.
Kill 2 multiplayer enemies with a single explosive.
In multiplayer, escape death 3 times by using the rope ascender.
Purchase a new multiplayer character.
Reach level 10 in multiplayer.
Buy every upgrade and character in multiplayer.
Reach level 60 in multiplayer.