Well .. if people spend more than a few minutes looking and actually were doing stuff it'd be only fair to mention them;
you needn't do that inside the description - I'd put them into the README actually.
Suggestion - if you develop in coop then have paper-and-pencil at the ready to jot down anyone you feel should get credit :-)
Oh .. and .. spending more than 10 minutes for publishing/preparation is by no means a bad sign - rather the reverse IMHO.

I don't think I can name anything that other people have done. I know someone helped me with the particles for the smokestacks, and someone made the original building entrance to the internal room (They made the entrance, I morphed it into what it is now - and actually kicked him because after doing that he started insulting other players). Other than that, things have come and gone so drastically that I can't point to anything not my doing.

Not being a jerk, just forgetful. If someone feels they're important enough to be mentioned for such a stupid little Sauerbraten map, then I'll add them and they can gloat about it to their friends that they contributed to tha best map evar.