Pescatore is a puzzle game, developed by Tierheit and meant to be published by Sunsoft. It was cancelled, but was briefly revealed to the public in spring of 1991 at Nintendo's Shoshinkai Show. The gameplay in Pescatore borrows the gameplay from PuyoPuyo and changes the rules slightly to require less skill and more luck.
Tire and bicycle manufacturer Bridgestone produced this piece of Famicom software to help its customers build their own custom bikes from the company's assortment of parts. Radac Tailor-Made was thus only given out to Bridgestone dealers, who would probably set it up in their shops so potential customers could play around.
Besides illustrating just how pervasive Famicom culture was in the '80s, Tailor-Made is now one of the rarest Nintendo cartridges on the secondary market.
Parody World: Monster Party is the Japanese release of Monster Party, and was originally intended to be much darker and more morbid than the relatively light-hearted version that was ultimately released to American gamers. No version of the game was ever released in Japan. The unreleased Japanese Famicom version was leaked online in August 13th, 2014.
Titan Warriors is a cancelled shoot-'em-up that was developed by Capcom for the NES / Famicom, in 1988. The game was meant to be a sequel of Vulgus, an arcade shooter developed and published by Capcom in Japan in 1984.
Originally slated for release in 1991, Bio Force Ape allows you to play as a pet chimpanzee who must rescue his family by taking the mysterious Bio Force serum and mutating into a pro wrestler. It was the recipient of an extremely positive profile in Nintendo Power — “extremely positive” being NP‘s default setting back in the day — but then vanished, presumably never to be seen again. The archivists at "Lost Levels" not only acquired the long-lost prototype cartridge, but uploaded a playable version of it to the Internet.