Shouldn't there be suggestions and request forums? Anyways... this might be off topic.
Since I really stink at map making I think I would like to just pass this idea to the pros, though I don't consider it would be a good idea... I was thinking of a tower defence based game in tremulous. Beforehand I had tried to make a map for a TD, where aliens have to do the rushing while the humans defend, turns out I couldn't finish it without the surfaceparm nodraw/nonsolid walls added into it (I know I stink

). Overall I don't think this is a good idea, but it is a thought. I already know that Tremulous is already related to this kind, but I think there should be one game type where just humans defend and another game type where just aliens defend, instead of both humans and aliens needing to attack and defend at the same time (at least we get a little more comfortable, right?).