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