Finished, shelved, and never released — the games that almost were
Star Fox 2 was a complete, fully playable sequel to Star Fox for the SNES that Nintendo finished and then shelved in 1995 to avoid undermining the N64's launch, remaining unreleased for 22 years before appearing on the SNES Classic Mini.
Thrill Kill was a completed four-player PlayStation fighting game featuring extreme violence and sexual content that Electronic Arts refused to publish after acquiring Virgin Interactive, cancelling a finished product weeks before its scheduled release.
Bio Force Ape was a near-complete NES action game by Seta Corporation that was cancelled before release in 1991 and believed lost for two decades before a prototype cartridge was discovered and auctioned in 2010.
Dinosaur Planet was Rare's ambitious N64 action-adventure featuring original characters Sabre and Krystal on a world of warring dinosaur tribes, which Shigeru Miyamoto personally requested be reframed as a Star Fox game, eventually shipping as Star Fox Adventures on GameCube in 2002.
Sonic X-treme was Sega's long-gestating attempt to bring Sonic the Hedgehog into 3D on the Saturn, a project that cycled through multiple engine designs and development crises over three years before being cancelled in 1996, leaving the Saturn as the only Sega platform without a mainline Sonic game.
Castlevania: Resurrection was a 3D Castlevania game in development for the Sega Dreamcast featuring new protagonist Victor Belmont and returning character Sonia Belmont, cancelled by Konami in 2000 after the Dreamcast's commercial trajectory became clear.
Mother 3 spent nearly six years in development as a Nintendo 64 title before Nintendo cancelled it in 2000 after the game's scope had expanded to unmaintainable scale, eventually shipping on Game Boy Advance in 2006 in a scaled-down form that was never officially localised for Western markets.
The 1997–2001 era of Duke Nukem Forever was 3D Realms' first attempt to sequel Duke Nukem 3D, cycling through two complete engine rebuilds in four years and becoming gaming's most famous development hell before the rights were sold and a different game shipped a decade later.
Airworld was the planned fourth and final chapter of Atari's SwordQuest series — an ambitious multi-game contest offering gold-and-jewel prizes worth $150,000 in total — and was never developed after the 1983 video game crash destroyed Atari's finances and ended the contest.
The scrapped first version of Resident Evil 2, thrown out when its own creators judged it simply "no fun" and rebuilt from scratch into the 1998 classic.
A finished Dreamcast port of Half-Life — complete with the exclusive Blue Shift expansion — cancelled a few weeks before shipping when Sega abandoned the console.
The dinosaur-brawler sequel that was cancelled in the middle of arcade location tests, surviving only on a single public cabinet and, eventually, a purpose-built emulator.
An Ultima game in name only, released on cassette for the VIC-20 in a run of a few thousand copies and never marketed — it vanished so completely that for years collectors doubted it had ever existed.
Atari's sequel to Marble Madness added flight, invisibility, and pinball minigames — then died on location test in 1991, unable to compete with the Street Fighter II machine next to it.
A genuine Super Mario World sequel, built for the Philips CD-i by an American studio, which Nintendo actually approved of — before the CD-i's collapsing sales killed it at roughly 80% complete art and 30% code.
A British studio fitted every room of the 1996 PlayStation original onto a Game Boy Color cartridge. Capcom looked at the result and decided it would rather not release it at all.
The sequel to the N64's ball-guiding glove platformer was most of the way finished when it was cancelled — reportedly because too many cartridges of the first game had been made.