Pong
Two-hour pong! Witness the result of my self-imposed challenge to write the proverbial Pong clone in under two hours. I had been so long coding dreary university assignments (oh frabjous day and whatnot) I needed to prove to myself I could actually code something fun. One interesting twist in the implementation is the use of separating axis theorem to handle the collision detection. The artificial stupidity (or 'AI', if you are willing to exaggerate) simply attempts to match the centre of its paddle to the current position of the ball when the ball is approaching, and otherwise attempts to centre its paddle.
Check out the hacked-together source code then download the executable JAR and play! Controls: A and Z move the left paddle up and down respectively, Up and Down move the right paddle.