JJSignal Some games definitely have more input lag than one would think, or just don’t play ball with emulators like they would on real machines. I’ll definitely have to try Usagi na Panic on a 9821Ce2 when I get the chance.
Re: Briganty, that’s likely some kind of copy protection crack. The game dump, among many others, likely came from Perfect Dark, a highly-encrypted Japanese P2P network that’s proven to evade surveillance by national cyber-sec authorities. (It’s very slow and limited in functionality, but it gets the job done!) Anyone trading pirated PC games over PD would likely have cracked it beforehand, hence the bugs when moving in and out of the manual prompts. Commercial/preserved floppy copies would prove or disprove this, or maybe just a simple look into a hex editor to spot any suspicious strings.