When I look at the Atari Arcade, I get a bunch of gobbledygook but if I click on individual links to individual games, I get an interesting experiment in HTML 5.0 demonstrating old fashioned character-based-graphic style games. Here are the links, but I suggest right-clicking and opening in a new window or tab so you can more cleanly shut them down if you get stuck. In other words, attempting to use the most advanced web-based programming language/markup tool to emulate ancient games is kind of like Dr. Who crossing his own time line and all sorts of bad things can happen.
The Atari Arcade
When I was in Middle School, I wrote my own TTY aware Lunar Lander program that ran on a Univac 1108, and later, a version of Pong that ran on a TRS80. What did you do in Middle School?