Many moons ago in around 1983 (When I was 16) I wrote a computer game which I finally sold when I was 19. The download here is a version from 1987. There were two production releases of the Spectrum version.
It sold about 50,000 copies for two Z80 machines used in Europe around that time. I have included below some links to allow you to download an emulator for one of the hardware platforms and then a copy of the memory image of the game. The sound is highly objectionable so turn your volume down before you run it.
The keyboard controls are the keyboard rows containing:
Download the following emulator by opening the exe wizard that downloads:
Download the game itself to a known directory
Run the emulator and from within the file menu of the emulator open the BRAINACH.Z80 game file.
To give you a little history (as if you wanted it!) I licensed the game to a company called CodeMasters from whom I received royalties while I was a student and to whom I eventually sold all rights. It was a 'zap-zap' game in a style which later became known as a 'platform game'. The game sold over 30,000 copies in its original form mainly in the UK and Spain. The hardware used was a Zilog Z80 based 8 bit machine called the Sinclair ZX Spectrum which fortunately now has a PC emulator so you can run the game on your PC. While I was a student I ported it to another Z80 based CP/M machine, the Amstrad CPC. This sold well in Germany and the Spectrum version was also remarketed in eastern Europe when the machine was manufactured in Portugal under license and exported.
The code was written as Z80 machine code in decimal data statements of basic programs which generated audio cassette blocks of data which could be loaded into sections of memory of the computer. The code could then be executed and tested by loading up all these modules from audio tape. After each test it crashed or worked and either way you then went back to the data statements made a further change and regenerated that block. You then loaded all the blocks back again for the next test. In order to edit the graphics I wrote a sprite manipulation package and a light pen driver and editing tool for the backdrop.
There was another version of the game with genuine music rather than load sound during the high score table routine. Somehow the doesn't appear to be in this version. The CPC memory images floating around the web have the improved sound.