You say that the CPC version is only 13K in size. I see you used a cracked version from NVG, and most of the cracks on NVG are compressed. The uncompressed game is 23,200 bytes in size (about 22.6K).
Having watched this video and had one quick go at the game again (and I do mean quick!), I think my
review of Speedzone from many years ago was rather generous!
