This version of Thunder Dragon 2, released just a month after the initial version, suggests updates or refinements to the original October release. It could be a bug fix update or possibly an updated version that is enhanced. This would imply an iterative development cycle, reflecting improvements based on the initial release or other feedback.   Again the developer and publisher remain uncredited.

Thunder Dragon 2 (9th Nov. 1993)

Thunder Dragon (9th Jan. 1992)