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.
Reach level 60 in multiplayer.
Kill 2 multiplayer enemies with a single explosive.
Purchase a new multiplayer character.
Kill a zip-lining enemy player in multiplayer.
Survive 10 explosions in multiplayer.
Complete a match in all multiplayer modes.
Complete the game.
Fully mod and completely upgrade any weapon.
Purchase all skills in one category.
Kill 35 enemies with the pistol.
Perform 50 headshot kills in the single player campaign.
Loot 200 enemies.
Find 25% of GPS caches.
Kill 25 unaware enemies.
Collect 5000 pieces of salvage.
Force an enemy to drop dynamite that kills two people when exploding.
Perform 15 finishers.
Kill 50 enemies with the bow.
Find 25% of all documents.
Complete one optional tomb.
Reach level 10 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.
Find 75% of all documents.
Collect 25% of all relics.
Collect 75% of all relics.
Find 75% of GPS caches.
Find all documents, relics and GPS caches.
Purchase all skills in all categories.
Fully mod and completely upgrade all weapons.
Kill and loot 10 large animals (deer, boar, wolves).
Kill and loot 10 small animals (rabbits, chickens, rats).
Kill and loot 10 flying animals (crows and gulls).
Kill 75 enemies with the rifle.
Kill 40 enemies with the shotgun.
Rope pull 5 enemies off edges.
Shoot 10 enemies off zip lines.
Incapacitate 25 enemies with dodge counter.
Complete all optional tombs.
Complete one challenge.
Complete all challenges.
Shoot a bundle of dynamite out of the air.
Kill FeeFee the crab.
Complete all conversations with the Endurance crew.
Kill 20 enemy players in multiplayer using a turret.
Revive a teammate in a multiplayer match.
Win a ranked match in every multiplayer mode.
Kill 10 multiplayer enemies using your melee attack.
In multiplayer, escape death 3 times by using the rope ascender.
Buy every upgrade and character in multiplayer.