Here is the full list of all 39 Ben 10 achievements worth 1,000 gamerscore. It takes around 6-8 hours to unlock all of the achievements on Xbox One.
Complete the objective!
Purchase every Boost for each alien.
Purchase every Boost for a single alien.
Discover a single Sumo Slammer card.
Destroy 5 objects with a single thrown enemy.
Complete "The City" in 15 minutes or less.
Achieve a combo of 50 or more hits.
Achieve a combo of 100 or more.
Hit 5 enemies with a single rolling Tweedledee.
Destroy 5 Bumblebees with a chain reaction.
Defeat three enemies with a single Four Arms throw.
Defeat 6 enemies with a single Cannonbolt roll.
Defeat 3 enemies with a single use of Heatblast's combat ability.
Hit 5 enemies with a single shot from Grey Matter.
Defeat 5 enemies with a single use of Wildvine's combat ability.
Defeat a Pie Juggler before their pie hits the ground with XLR8’s combat ability.
Dodge Weatherhead lightning, then hit the attacking enemy by using Upgrade’s ability.
Hit 10 enemies with a single use of Diamondhead’s ability.
Defeat 3 enemies with a single use of Overflow’s ability.
Stun a self-destructing Bumblebee with Stinkfly’s ability.
Complete 30 Bonus Objectives
Defeat the Weatherhead Prime without taking damage.
Defeat 10 enemies with a single Ultimate Ability
Defeat 2 enemies with a Weatherhead Drone.
Defeat an enemy as each of the 10 aliens in one fight.
Defeat 10 enemies as Ben.