Granted it is very brief and not entirely true to the original gameplay, it is still downright impressive that something like this can even be accomplished with a web-based scripting language.
If you are interested in seeing how the whole thing works, you can sneak a peek at the uncompressed code.
Keeping with the 8-bit video game theme of this post, Tetrageddon.com is an odd Flash site. The style of the music and graphics is in homage to the 8-bit videogames of years past but there are no explicit directions about what to do. Instead you are left to fend for yourself exploring the site and uncovering the wacky consequences of your voyage. The whole thing is “CENTALLY MHALLENGED” to borrow from the sites page title.
Tip: on the main page hold the up arrow key and make sure you allow pop-ups for the site.
If anyone can figure out something interesting to do at Tetrageddon.com let me know in the comments.