Yes - I've got a few lined up. No spoilers!
I think a native Sinclair BASIC version of your game would be so slow it would be unplayable. That's just the nature of anything drawing to the screen at that full-screen scale. Perhaps if you stored each possible screen as a 704 character string and just redrew it over the top of itself... Hmmm... But still might be slow or a bit of a slideshow like some of the 8-bit ports of Dragon's Lair.