Ad Infinitum is a circular based (sort-of) netmap for two or more players though I would suggest three or more. There are two versions of the map - Light and Heavy. The Light version has less powerful weapons and aliens while Heavy has all the guns (exept for the flamethrower) and big aliens.
Hope you enjoy!!
(I certainly enjoy playing it, but something makes me think that I could have a biased opinion.)
There are two maps with this Pack
Cyborg Central - A large area map good for Multi Player carnage. Two variations - Light and Heavy
The Level of Lighting - Just an interesting idea that, in the end, worked quite well. It's sort of incomplete but it might end up being the start of a solo one day.