The Game: It’s quite simple, really. You’re the pilot of a ground-based mobile weapons platform, and there are buttloads of alien meanies headed right for you. Your only defense is a trio of shields and a quick trigger finger. If your cannon is destroyed, its pilot must run for cover; each of the three shields contains an extra cannon. When all three shields are gone, the alien commander – a kind of spaceborne crab – will descend to nearly ground level and hunt the helpless pilot down. Ten rounds of this decide the outcome of the war. (Magnavox, 1980)
Memories: Alien Invaders – Plus! was the first Odyssey 2 game I got hooked on, and my mother just thought it was riotously funny, especially the bit where the giant space squid floats down from the top of the screen to chase your unprotected gunner around when all of your defenses have been depleted.
A prime example of the Odyssey team’s approach to adapting popular arcade games without all that expensive licensing, this title obviously uses Space Invaders as its inspiration, but it also changes the elements of the original around enough to make it a different game. 
Countless battles won in Space Invaders couldn’t guarantee you success when the crab-like mothership monster came zipping down the screen to get you.
Make no mistake, this is not an easy game to win – on few occasions have I beaten the machine by any distinguishable margin!