How do you beat Doomsday in Justice League Heroes

As soon as the game starts, go to the control panel and activate the force field. Then go to the left of the control panel and activate the laser turret. Doomsday will be trapped within the forcefield and be targeted by the laser turret. Go back and reactivate the forcefield before Doomsday moves away from the forcefield region then go back and activate the laser turret again. Repeat about 4 times until Doomsday is defeated. Good luck!