Sarah, can't you release a .d64 version, as for Zeta Wing? I bought it right now but I haven't a Kung Fu Flash cartridge so I can't play with my C64 :-(
I didn't see there isn't the d64 version before to buy :,-(
Given the 633KB cart, converting it to d64 is probably a large project. For starters, you'd need to slice it up among like 6 disk sides, and depending upon how elements are used, you might need to make major changes to the game logic. Even a d81 might be hard with inserting disk read logic everywhere and changing the memory use pattens.
In short all I'm saying is it's a lot of work.