13 maps. Eight are already here, as Vertigo Maps. The other 5 are worth the download... generally, interesting-looking maps. (Some look better than they play.) One of these will make you go blind if you play it too long...

Very simple, but it plays well. High carnage with anything more than 2...

A pretty incredible 26-level scenario from a Danish mapmaker. Quite a bit of new art, as well as art "borrowed" (with credit) from other work... The storyline is conveyed in chapter screens-the terms you find simply contain the secret terms from the original Marathon, in case you missed them the first time around. Some unpleasant tricks are here (save whenever you get the chance, since there are more than a few dead ends), and some silly stuff (pictures of naked women in the marine jail cells, the bobs are now boobs (and pretty well done, too), that sort of thing)

Four maps, none of them really playable. They're mostly idea maps... sort of trying out new architectures. A couple would make nice additions to existing maps...