Well, take a look at some other things that rank high in various search engines.
E.g. the Jazz 2 Webring still ranks high AND is, I believe, accessible. Post a message there.
E.g.2. all the review pages that get listed. Some of them have a "suggest a link" feature. Make use of it!
E.g.3. the official G.O.D. games Jazz 2 page. It has a links section and as far as I know it's still accessible by the admins.

As for Alltheweb.com, it's covered. (just search for Jazz Jackrabbit and see what comes up in the top 3)