Mortal Kombat for Game Boy was released on September 13, 1993 in North America.
On this GB version of the game, Cage (from the original Arcade game) was taken out.
Known export releases:
"Mortal Kombat - Shinken Kourin Densetsu [Model DMG-C9A]
[UK] "Mortal Kombat [Model DMG-C9-UKV]
"Mortal Kombat [Model DMG-C9-NOE-1]