I was just thinking what was the first game I wrote, and it was actually a project for a class that was 1000% not game related.
The project *requirement* was, "write a Windows GDI application". IIRC GDI stands for GodDamnIt /j
What I *delivered* was a from-scratch pinball machine game engine.
I later found that the college put it in their, "good previous student projects to build things on" directory.