Here is the full list of all 50 Titanfall 2 achievements. It takes around 15-20 hours to unlock all of the achievements on Windows.
Beat Pilot Anderson's Gauntlet ghost recorder time
Place in the top 3 on the Gauntlet scoreboard
Complete training
Fully Powered BT-7274
Defeat Kane
Keep Lt. Shaver and Lt. Freeborn Alive
Enter the World Foundry
Climb the Sideways Town
Defeat the Reapers in Ash's Simulation Dome
Defeat Ash
Kill a Caged Prowler in the Wildlife Research Labs
View Anderson's first Holographic Log
Find the Arc Tool
Power the Beacon
Retrieve a working Uplink Module
Defeat Richter
Use the Arc Tool to activate a Stalker rack
Locate the Ark
Defeat Viper
Secure the Ark
Call in a new BT
Complete the rising world run
Defeat Slone
Destroy a Titan with your Burst Core in the Campaign
Destroy a Titan with your Flight Core in the Campaign
Destroy a Titan with your Salvo Core in the Campaign
Destroy a Titan with your Sword Core in the Campaign
Destroy a Titan with your Laser Core in the Campaign
Destroy a Titan with your Smart Core in the Campaign
Destroy a Titan with your Flame Core in the Campaign
Destroy a Mercenary Titan with a melee execution in the Campaign
Destroy 3 enemy Titans with 1 Core ability in the Campaign
Kill 25 infantry in 2 seconds as a Titan in the Campaign
Destroy an enemy Titan as a Pilot in the Campaign
Shoot and kill 3 enemies in a row while wallrunning as a Pilot in the Campaign
Shoot and kill 3 enemies in a row while sliding as a Pilot in the Campaign
Rodeo an enemy Titan in the Campaign
Perform a melee takedown while cloaked in the Campaign
Acquire 6 or more friendly Stalkers at the same time in the Campaign
Complete the Campaign on Regular
Complete the Campaign on Hard
Complete the Campaign on Master
Collect all of BT's loadouts in the Campaign
Find 10 Collectibles
Find 25 Collectibles
Find All Collectibles
Win a multiplayer match
Customize a multiplayer loadout
Join a multiplayer network
Complete Special Operation 217