Otto Matic

In 1957, evil Brain Aliens from Planet X sent a fleet of flying saucers to Earth to abduct humans to other worlds as slaves to the Giant Brain. Luckily, robot police named Otto Matics patrol the galaxy and you control one whose mission is to rescue humans from different alien planets and defeat the Brain Aliens and other alien followers.

You start on Earth and try to prevent abductions and also collecting rocket fuel while defeating the aliens. Use 7 different types of weapons through 10 levels while battling 25 types of aliens like giant radioactive killer vegetables, metal beasts, and alien clowns in hovercraft bumper-cars. You can ride in a bubble across noxious lakes of slimy goo, or ride a zip line in certain areas. At one point, you can also control a flying saucer to attack alien fortress. There's also a radioactive potion you can drink to grow to 50 feet in size.