It refuses to run even if the disc is in there, it's probably a copy protection related failure (and knowing how upd765 fails protection checks in PC-8801 that's very possible ...)
EDIT: it also changes the floppy properties in the CMOS (gets hardcoded to 360 KB)
A-Train
I'm still in love over the pixel art that is this game, also considering it's just a 640x480x16 mode.