This revision of Crack Down for the Sega Genesis represents an updated version of the game, released in Japan. The 'Rev A' designation indicates that this is a revised version, likely improving upon the original release by fixing bugs, glitches, or possibly making minor gameplay adjustments.  These revisions are common in game development to address issues identified after the initial release.   The developers would be the same as the original game, and information about them will likely require further research on Japanese game releases.

Crack Down (Japan) (Rev A)

Corporation (Europe)