Toki

Canceled Spectrum version

A Spectrum version got as far as being previewed by several magazines, and many screenshots exist, but it was never released.

Never released Atari 7800 version

Over 20 years after the initial release of Toki, a playable beta version of a Toki port for the Atari 7800 was discovered. It shows a 1993 copyright in the title screen and is only runnable on PAL systems. It is a quite accurate conversion of the arcade original, but the last level of the coin-op original is missing in this version. Also most bonus items are missing and some bugs are in the game. It is unknown why this nearly complete port was never released. Source: Betaphasegames