Hi I'm new to the forum so I'm not sure if this the right place to post this. I've been reading "Racing the Beam" and thinking about working on a homebrew, but I've also been playing around with the programming language/tool Scratch. So I started a clone of the Atari 2600 Asteroids since it is one of my favorties. I thought there might be some interest in looking at and hacking what I've done.
Asteroids (sort of)
I also found two other (and much more refined 2600 games in the Scratch projects pages):