SixSixSixFlags is a text-based adventure game I wrote as an assignment for one of my first-year computer science courses. I'm pretty sure the assignment required that the game have four to six rooms -- I got a little carried away and gave it ~16 different areas, depending on whether or not you count the secret passageway and boss fight.
This was one of the first games I ever wrote from scratch, and while the code itself could be refactored and improved with the knowledge I've gained since then, at the time I really pushed myself to see how complete and entertaining of a game I could create with my limited experience and toolset.
This project challenged me to form a scalable architecture before I knew what an 'architecture' was, what 'scalable' meant, or what 'objects' were for. I had to creatively overcome obstacles, and did so, propelled purely by self-motivation.