Similar to the previous release, Mortal Kombat II (USA) (Rev A) represents a revised version of the game released in the United States for the Super Nintendo.  Revision A likely addressed bug fixes, minor gameplay adjustments, or other improvements over the original US release, improving stability and user experience.   The specific changes may be minor but crucial for the game's overall stability and playability.

Mortal Kombat II (USA) (Rev A)

Mortal Kombat II (Europe)