Laserblast

Billy's never been able to fit in where he lives...suddenly that's not a problem anymore. A desert exploration leads to an explosive discovery for Billy - his own personal laser gun. Each time Billy fires the laser, he begins to mutate, little by little, into an alien. Possessed by the new power in his hands, Billy terrorizes the town with the awesome alien device. Now it's a race against time before the aliens return to claim the weapon...and his life. (official distributor synopsis)