Version differencesDespite being a port of the arcade version, the SNES version is not entirely accurate to the original.
Aside from the tweaked difficulty and additional armaments, two entire levels were cut from the arcade: a 3D stage which involved avoiding cave walls from a first-person perspective behind the Vic Viper, and a crystal stage in which you were challenged by crystal blocks blocking off areas like a maze.
The SNES port also has extreme slowdowns on the real console. The same is true for the Wii version which is a ROM of the original SNES game running in an emulator.
Information also contributed by haynor666