Correct me if I'm wrong higher powers, but I think it comes down to exactly the nature of the game:
Unlicensed reproductions/pirate games (inc pirate multicarts) - not allowed
Homebrews (ie completely new games) - allowed
Hacks (a mix of stolen IP and new programming) - not sure tbh
I think this would fall somewhere between hack and homebrew so not sure on its eligibility. Though I think I would lean towards include.
Correct me if im wrong on definitions and whats allowed in please.
PS - Sachen I believe are just unlicensed games which are allowed. Essentially homebrews from the same era as original release
I'd only clarify that hacks themselves are not allowed. A hack is where someone steals the code of another game and makes slight modifications.
In the case of Shui Hu: Feng Yun Zhuan, it's new code, even though it does borrow a lot of inspiration from other sprites (although they are not direct rips, but just takes the overall design and reworks them into that game engine). Honestly, most fighting games have to have generic baddies, and there is a lot of similarity in them, so it would be tough to get that tight. I remember back when Capcom sued Data East about Fighters History and lost. Unless it is a direct rip-off, there is room for similarity.
Sachen games were original, and perfectly acceptable.