So Way back in high school I made this java applet game. I hope to someday perhaps get it cleanup and working a lot better, but here is what I was able to figure out in high school.
Download into eclipse and run it!
Space to move up and down, A and D to move left and right.
GPL 2.0+, Feel free to download and play with the code! See if you can't figure out a way to make it better, or have some inspiration for your own basic 2d application.