Hmm, that might be it! Haven't had a chance to play it, but it seems really familiar! Especially since they say that it was mentioned in PCG a while ago. Someone play it.
If you still have the magazine, could you possibly scan it and post it online? I'm currently trying to find an online PC Gamer archive, but posting it up here would benefit everyone in this forum.
I read a while ago (2-3 years) in a PC Gamer(?) magazine about a mod for I think Half Life 1 that put you against an unlimited amount of zombies. You had to build a fortress at the beginning out of many different components, such as force walls, and you could even build "machines" like a...