Stephen Firth - 01/07/2019
Should point out this was not written in Machine Language. It was written in a custom language called TCL (Test Computer Language) - not to be confused with the well known TCL (Tool Command Language). This TCL was written by David Firth - original author of the Atari800 emulator (https://atari800.github.io/) which has since spawned many ports and offshoots.
impressive game, pretty hard but nice on the eyes!