Was the game designed to run from boot or from the click of an icon. What is the game and how is it structured. If its an adf or dms then use blitzer and or write dms from the shell and decrunch to floppy. If an lha then the files may have an execute icon so look through the drawers and files. Not sure what it is that you are trying to do without more information on the game and the files involved. The boot will be necessary from the bootblock and you are right in trying to create this. However, there does need to be more direction such as a startup sequence but beyond that... I really am out of my depth.
More information needed really.
