What Changed from Killer Instinct 2 to Killer Instinct Gold?
The verdict in one line: Killer Instinct Gold is faithful to Killer Instinct 2 where the fighting is concerned, and different almost everywhere else. The changes were driven by one documented cause, the data storage restrictions of the Nintendo 64 cartridge, and Rare answered the losses with additions the arcade game never had. Both lists matter, so both are printed here in full.
THE COVER, AND THE MISSING ONE
One box exists. One was never made.

WHAT WAS LOST
Cut for the cartridgeWHAT WAS GAINED
Built for the homeWhat they did get, then, was the more complete home game wrapped around a thinner presentation: the same eleven characters, combos and environments, with the film removed and a practice room, a team mode and a tournament bracket added in its place. Reviewers at the time preferred the Nintendo 64 port to the arcade release in several respects, while feeling its graphical upgrades were insufficient. Both halves of that judgment start in the lists above.