PONG
As simple as it gets, re-written in Java and powered by OpenGL, this was a small project that turned out to be an extremely fun way to waste time and learn graphics programming. Featuring on-the-fly rasterized text rendering, basic physics and 2 player gameplay, it was a great achievement to finish this on my own.
A side note, this project is no longer developed, so the methods I have used for rendering/using certain elements of the engine may be extremely unoptimized in certain use cases, so please do some research before using my code! (Or just update it lol).
-Logiiq