Many, many years ago this project was began in AMOS basic, but has since been converted into pure Assembly language. Some AMOS memory bank formats are still used, though!
@lionstorm
I have changed the scrolling since the full beta release, I think the executable patch fixes it, could be wrong, don't remember (did you try it?). You are not the only one to suggest a high score table, in fact it was originally planned but not a very high priority compared to making the actual game, as I'm sure you can appreciate.