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