R.B.I. Baseball / Gauntlet (NES)

http://megalextoria.blogspot.com/2014/08/gauntlet-rbi-baseball-nes.html

Tengen wasn't particularly happy with Nintendo's licensing restrictions at the time (licensees could only publish up to five games a year) and sought less restrictive terms but Nintendo was having none of it. In a bit of subterfuge, Tengen got its hands on patent information for Nintendo's lock-out chip and used that information to release unlicensed games. As you could imagine, a series of lawsuits followed. Tengen also released a version of Tetris that is pretty rare and this also led to a lawsuit that Tengen lost. They were forced to recall most of their Tetris games which is what makes them rare today.

This particular ad features two of the four licensed NES games that Tengen released, R.B.I. Baseball and Gauntlet (Indiana Jones and the Temple of Doom and Pac-Man were the others), though they released many other unlicensed games, including unlicensed versions of these games. R.B.I. Baseball is one of the classic baseball games of the era while Gauntlet is one of the most famous arcade games of all time and one of my personal favorites. Both of these were excellent games though I have more experience with Gauntlet on the Commodore 64. Tengen also released games for the Sega Genesis, Atari Lynx, Game Gear, Sega CD, TurboGrafx-16, and the Amiga and Atari ST (via Domark) with much less litigation involved.