The Game: As the pilot of a lone space cruiser, you must try to clear the spaceways of a swarm of pesky and relatively harmless drone UFOs, but the job isn’t easy. You can ram the alien ships with your ship’s shields, destroying them (but forcing your shields offline for a few precious seconds during which anything could collide with your unprotected ship and destroy you), or shoot them (which also forces your shields down for a recharge). To that screenful of bite-sized chunks o’ death, add an unpredictable Killer UFO that likes to pop in and shoot at you, and suddenly being an interstellar traffic cop ain’t so easy. (Magnavox, 1981)
Memories: UFO! was the first “Challenger Series” game, which usually denoted a game that was an interesting derivative of an existing arcade favorite, in this case the popular Atari game Asteroids.
In the case of UFO! the game play is so strikingly similar, the only thing between Magnavox and an Atari lawsuit at the time of the game’s 1981 release was probably the Odyssey’s obscurity. The singular twist – aside from the relatively superior graphics of the Odyssey game – is that the your ship’s shields are up constantly, allowing you to ram the oncoming aster…uh, UFOs…at the cost of the 
shields disappearing for a second. Oh, you may think it sounds minor, but the nasty hostile UFO that actually shoots at you usually pops up while your shields are down. A most frustratingly addictive game!