Wreckage

You are in control of a laser base protecting a city from the ravages of alien flying saucers that resemble very angry jellyfish. They are dropping bombs all over the place, blowing craters in the ground, smashing up the roads, blasting the houses to bits and crumbling the domes, all under a hot blue summer sky. Your laser base can be moved left and right for firing while a vertical sight to the left of the screen affects the trajectory of the shot.