Here is the full list of all 38 Ben 10 achievements.
Defeat the Weatherhead Prime without taking damage
Defeat Queen Bee without taking damage
Complete ‘The Hive’ in under 15 minutes
Hit 5 enemies with a single rolling Tweedledee
Collect every Sumo Slammer card
Hit 10 enemies with a single use of Diamondhead's ability
Defeat a Pie Juggler before their pie hits the ground with XLR8’s ability
Defeat an enemy as each of the 10 aliens in one fight
Complete ‘The Tornado’ in under 15 minutes
Reach the top of the Weatherhead Tower without falling off
Complete ‘The Canyon’ in under 15 minutes
Complete ‘The Scrapyard’ in under 15 minutes
Defeat 6 enemies with a single Cannonbolt roll
Stun a self-destructing Bumblebee with Stinkfly’s ability
Completely upgrade all aliens
Complete ‘The Funhouse’ in under 15 minutes
Defeat Zombozo without taking damage
Defeat 5 enemies with a single use of Wildvine’s ability
Complete “The City” in under 15 minutes
Finish the game
Complete 30 Bonus Objectives
Collect half of the Sumo Slammer cards
Defeat 2 enemies with a Weatherhead Drone
Dodge Weatherhead lightning, then hit the attacking enemy by using Upgrade’s ability
Defeat Queen Bee
Hit 5 different enemies with a single shot from Grey Matter
Defeat 3 enemies with a single use of Overflow’s ability
Cause a chain reaction of 5 exploding Bumblebees
Defeat Zombozo
Defeat 3 enemies with a single Four Arms throw
Destroy 5 objects with a thrown enemy
Completely upgrade one alien
Defeat 10 enemies as Ben
Defeat 10 enemies with a single Ultimate Ability
Achieve a combo of 100
Achieve a combo of 50
Collect a Sumo Slammer card
Defeat 3 enemies with a single use of Heatblast’s ability