Full list of all 88 Titanfall achievements worth 2,000 gamerscore. It takes around 150-200 hours to unlock all of the achievements in the base game on Xbox 360.
The base game contains 35 achievements worth 1,000 Gamerscore, and there are 4 DLC packs containing 53 achievements worth 1,000 Gamerscore.
Reached the highest Pilot generation
Killed an ejecting Pilot with the Plasma Railgun
Won 50 Last Titan Standing matches
Won 50 Pilot Hunter matches
Unlocked everything
Played every gameplay mode on every map
Killed 10 ejecting Pilots
Won 50 Capture The Flag matches
Wallran for 5 kilometers
Won 50 Hardpoint matches
Earned 500 burn cards
Killed all Pilots during the evacuation single-handedly
Won 50 Attrition matches
Won every Campaign level as an IMC Pilot
Completed the Militia campaign
Won every Campaign level as a Militia Pilot
Snapped the necks of 10 Pilots
Became a second generation Pilot
Reached level 50
Played 50 Campaign matches
Killed 1000 AI soldiers
Hacked 20 Spectres using the Data Knife
Completed the IMC campaign
Killed 5 enemies by dropping a Titan on them
Reached level 25
Killed 5 enemies with one Arc Cannon shot
Completed all challenges for a single weapon
Rodeo-killed a Titan
Called in your Titan 25 times
Created a custom Titan loadout
Created a custom Pilot loadout
Finished as the top player on your team once
Survived an evacuation
Caught a projectile shot from a vortex with your own vortex
Completed training
Killed 25 enemies while wall running on Runoff
Killed 100 Pilots on War Games
Played every game mode on War Games
Played every game mode on Runoff
Killed 12 Pilots in a single match on War Games
Played every game mode on Swampland
Didn't touch the ground for 60 seconds on Swampland
Killed 200 enemies on Runoff
Won a match on Runoff
Won a match on War Games
Was airborne for 500 Meters on Swampland
Won a match on Swampland
Played every game mode on Export
Played every game mode on Dig Site
Killed 25 enemies while cloaked on Export
Killed 15 titans while you had a Titan Burncard active on Haven
Played every game mode on Haven
Killed 50 Pilots on Dig Site
Killed an enemy with the trap on Export
Killed 12 pilots in a single match on Dig Site
Won a match on Export
Executed 2 titans in a single match on Haven
Won a match on Haven
Won a match on Dig Site
Melee killed 15 enemies while cloaked on Backwater
Killed 10 Pilots as a Titan in a single match on Zone 18
Killed an enemy with Amped vortex shield deflection on Backwater
Played every game mode on Backwater
Played every game mode on Sand Trap
Killed 10 Pilots while Active Radar Pulse was active on Sand Trap
Killed 10 Pilots while stim was active on Zone 18
Played every game mode on Zone 18
Killed 2 Titans as a Pilot in a single match on Sand Trap
Won a match on Backwater
Won a match on Sand Trap
Won a match on Zone 18
Earned Gen 10 without using a Forged Certification on a regen challenge
Purchased 100 items from the Black Market
Completed 100 Daily Challenges
Earned at least 2 stars on 15 different maps in Frontier Defense
Won 10 games in a row
Earned 500,000 Black Market Credits
Unlocked 50 Titan Insignias
Purchase all Titan OS Voice Packs
Won 5 games in a row
Completed all Daily Challenges for a day
Earned a total of 50 Stars
Used 5 Titan Burncards
Earned 50 Battlemarks in Ranked Play
Discard 100 Burncards in exchange for Black Market Credits
Played a ranked match
Earned 3 stars for a single map and mode
Named a custom loadout