Here is the full list of all 50 Teenage Mutant Ninja Turtles: Mutants in Manhattan achievements worth 1,000 gamerscore.
Activated the ceiling switch during the battle with Slash
Completed a stage without being spotted once (outside of Missions)
Ate a pizza during the snapshots when a boss is defeated
Hung out outside of an enemy hideout for at least 10 seconds
Defeated 5 enemies at once by blowing up a Foot Soldier carrying a bomb bag
Completed Easy or Normal mode
Used a Combo Attack to defeat 6 enemies at once
Destroyed a helicopter
Traversed a total of 32 miles
Experienced all of the Krang UFOs' status effects
Found the secret room in the TCRI building
Destroyed 30 cameras and laser devices
Played online at least once
Used Turtle Switching to defeat 1 enemy with all 4 Turtles
Collected 10,000 Training Points
Traversed 1 mile in the Residential Area without touching the ground
Defeated 5 enemies with 1 drum can
Equipped at least one Emblem to your profile
Grinded rails for 300 feet
Completed the Tutorial
Complete Hard mode
Obtain 25% of all Collectibles
Obtain 50% of all Collectibles
Obtain all Collectibles
Traverse a total of 150 miles
Dismantle Charms 30 times
Upgrade 30 Charm Effects
Detonate 100 drum cans (including proximity mines)
Disarm 30 time bombs
Transport gold bars 30 times
Transport 30 bags of money
Transport 10 Chemical Weapons to a Portal
Transport 30 Krang Bombs to a portal
Protect 30 ATM machines
Protect 10 Pizza Trucks
Destroy a rampaging car with a drum can
Climb to the highest point in Karai's stage and do a little dance
Have all Turtles turn into zombies simultaneously by touching contaminated water
Defeat 10 Stone Warriors with turrets in Wingnut's stage
Defeat the 4 Krangdroids with your conventional weapons in Mega Krang's stage
Survive the elevator section at the TCRI building without taking any damage
Eat 100 pizzas
Enter the Pizza Room during the snapshots when a boss is defeated
Have Mikey do his co-op move finishing pose during the snapshots when a boss is defeated
Have everyone perform a Communication Action during the snapshots when a boss is defeated
Defeat 5 enemies with both Turbo Mode and Berserk activated
Defeat a Secret Boss
Complete a gold bar mission without the carrier being hit even once
Defeat Rocksteady and Bebop by letting them get run over by a train
Use any character at least 50 times