
You did great. I think it's a good approach to use the top for graphics so you earn an extra 4k of ram

From the code here: "https://github.com/oric-software/BattleZone4Oric", i think it's not a good idea to use multiplication and division directly. Use mapping for everything (tables).
Operators to display text on the screen (print, printf) are quite slow. Don't use them if you want speed. Аnd one more time: use mapping for everything (with the mapping I achieved very good results)

I think it has worked out quite well so far. I look forward to playing this game.