This is my version of Valve’s game, Portal.

In this puzzle game you proceed by solving each Test Chamber by using portals, two connected ‘doors’ or ‘gates’ that conserve your momentum, direction, and velocity.  You can use such properties as gravity, terminal velocity, friction, momentum, etc.

I didn’t use any third-party libraries or code.  I learned how to add audio from http://rbwhitaker.wikidot.com/java-play-audio.  

I started with a version of this game that I had made for my APCS class in high school, but I changed the implementation of basically everything (how levels are written, how data is stored, how it responds to key presses and mouse clicks, etc.) and added better graphics and movement, status bar, reset button, instruction button, audio, etc.

To play this game download and unzip the files from here: http://tinyurl.com/o3ugol4
From your computer’s terminal, navigate to the directory containing the unzipped files and run: javac *.java & java Game

Enjoy!