Mortal Kombat Revelations is a fan-made project, a ROM hack, built upon the engine of Mortal Kombat II for the Sega Genesis. It is not an official game released by Midway Games.  The exact details of its features and gameplay modifications will depend on the specific version of the hack.  Such fan projects often showcase the creativity of the gaming community and their desire to expand upon existing games.

Mortal Kombat Revelations

Mortal Kombat II (World) [Hack by Smoke v0.70] (~Mortal Kombat II Unlimited)