Pony Metal U-GAIM (lost MSXII video game; 1980s)
Pony Metal U-GAIM is a Fan-made series parodying Heavy Metal L-Gaim and Creamy Mami. A number of books, comics, and garage kits released between 1985 and 1988 (by Fruit Company), a 3-minute Promotional video/OVA (by Sunrise workhorse studio Anime R), and MSX2 game was planned. The series was very popular umong the respective fan communities. Other spin-offs where created through out its life time. 
ASCII was planning to release a game based on U-Gaim for the upgraded MSX2 and commissioned a 3-minute promotional video in anticipation. While the Animated Promotional video was being sold through General Products. The game never saw any sort of release or much of an announcement. Screenshots and magazine, and comic blurbs hinting at the possibility of a computer game being made. Once the Animated Promotional video gained traction online, photos from foca_snark on twitter where posted of the unreleased game. He has been stated that this is all the data he has from the game.