My first paid programming work, from my work experience at Penrhyn Quarry. Made for an open day and they gave me 50 quid after the fact.
I bought a USB 3.5″ disk drive to attach to me Mac, and the disk just worked, and the emulator just worked too:
Here is the Pascal source code:
And a video of the game being played (though sadly with no audio – you will have to imagine that!)