[Edited by tsagoi, 12/13/2008 9:15:48 PM]

It does get a bit repetative in the end though.

Most recommendations I've see say to build your maze, but then concentrate on upgrading 2 platforms that will get the most alien passes.

So if the alien has to talk past it twice on the way to your power cores, and twice on the way back, that platform gets 4 total attack passes on the aliens.

best,
Cal