Well, not exactly one-page. Tom’s game turned out to be about 2.5 pages in length, but you will not believe how cool it is. It’s basically a little Zelda clone in 3D, with an overworld and four (count them, FOUR!) dungeons to explore, each one with its own tricks and traps.
Head on over to his site for the code and the executable. Be sure to read the readme, or you’ll probably have trouble figuring out what is going on.