This was my first game that was created purely using Java. I was trying to get to grips with the Java API, Graphics2D, and compare it with other external libraries (which I am currently working on now).
This entire game (as well as engine), was made from scratch, finding small pieces of information online when needed. Some logic was not made by me (advanced game loop), but that approximately 30 lines of code.
No attempt was made at making an appropriate GUI interface or game art.