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