The class that runs the game is Game.java, and is a good place to start looking through the code.
This was the first large program I wrote, and there are certainly some design choice I would change if doing the project today.The most glaring of which is likely the lack of a Level class that would have avoided the need for the many different arrays at the start of the Game class.
To run the game, you will want to compile and run the Game.java file, which is an applet. You can also open the _Click HERE FOR PC.html file which should run the applet in your browser, if your browser is set up to allow applets to run.