Copy protectionThe copy protection for this game (DOS) used the back of the box.
Japanese versionIn the Japanese version the intro is not told in text form but as a sequence in which a girl is kidnapped.
SNES versionThe Super NES port features an overworld map in order to choose the levels (unlike the arcade/Genesis versions all of them have to be played), which were longer, plus some bonus stages (either in the levels or out in the world map). The final boss is also different and there is only one ending. In the Western version some bosses have additional green colour on them.
Information also contributed by Dan K