According to programmer Brendan Gunn and QA tester George Andreas, a SNES version of Killer Instinct 2 was developed and completed on short notice after several team members left during development, but Nintendo never released it. Andreas speculated that it was pulled from release so Killer Instinct Gold could receive more promotion as the port was developed late into the SNES' life cycle. In 2015, Rare co-founder Tim Stamper posted a picture to Twitter which contained a cartridge PCB labelled "KI2 SNES V0.2", indicating that a build still exists in his possession, but has yet to see release.

The game's files cointains data of multiple unused alternate endings for various characters such as Maya and Jago. These endings weren't properly implemented due to time constraints.

There were plans to include a vampire character in Killer Instinct 2, however the idea was eventually scrapped. The vampire's stage theme, "Bloodlust", however, was salvaged and made into the theme of Count Batula in Conker's Bad Fur Day.

A vampire character wouldn't be added to the Killer Instinct series until 2016, with the release of Killer Instinct's season 3 character Mira.