Marathon (First Person Shooter)

I can't believe I didn't post about this game before, but I've been playing Marathon, A game by Bungie, the same people who made halo! I play it because even with my dial-up I can play online. Also, if you happen to have an old mac, like OS 9 (I don't) you can make your own maps easy! I've posted a link to it also (on the great list of knowledge), it's worth the download, but it's complicated, so have some time on your hands before beginning.