Ed Fries, who used to run game publishing for Xbox, has created a demake of Halo for the Atari 2600. I'd talked to Ed about the project when I was exhibiting A Slow Year at the IGF this year, and he'd been kind enough to show me some late stage builds of the game. The result is excellent, both as an Atari 2600 game and as a demake of the Halo titles.
Here's Ed's post about the project on AtariAge, and you can download the ROMStella. Much to my chagrin, I'm missing Classic Gaming Expo this weekend, but I understand that Ed and Al Yaruso of AtariAge have made some carts for the event, so if you're there you should try to pick one up.
Apart from lighting a fire under me to release A Slow Year (it's done, really, just working on packaging), Ed's game reminds me that I should share with my readers here the results of last term's Atari remakes and demakes class. There were some good ones, including superb demakes of Minesweeper and Street Fighter for Atari 2600.