Platy-co's
BIG FAT HISTORY
OF THE ARCADE
VOLUME TWO:
The ripoffs strike back!
One of the most guaranteed facts in the arcade business was, for every Pac-Man, there had to be a million Pac-Man rips that were barely legal. The problem with video games is that you can trademark characters and pictures, but not the basic idea of the game itself. The inventor of Pong was able to copyright the name Pong and the game's exact circuitry, but the basic idea--electronic tennis--was public domain and is still ripped off today by the makers of scum like "Mario Tennis" and "Electronic Arts presents Serena Williams Volley 2001."
Space Invaders
Alien Invasion
Take a guess
Super Invaders
One of these is Space Invaders. The others are: Invader's Revenge, Super Invaders, and Alien Invasion. Some difference, huh?

What's with the "For Amusement Only" warning in "Invader's Revenge"? Hmm.....
Apparently, selling Ms. Pac-Man was okay as long as you renamed her "Pac-Gal." The scary thing is that several retailers would actually fall for this.
More history right here!