Sorry about my lack of progress reports here. The Compute Games disk is both more difficult and interesting than I thought it would be.
I've actually had the WIP2 version running in emulation. I rather like the little character; he reminds me of Lester Chaykin (Another World), but I couldn't find a joystick to use with my PC, and then I didn't have time to write it to floppy to use in my A500.
I'm still following this thread with much interest, so keep up the good work!