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