I played with Chet and two other Valve guys, and later again with spud and two randos.
We were all pretty underwhelmed by it. It LOOKED nice, but the gameplay was pretty lacking. There is no sense of direction in the maps, save for the occasional arrow sign (they overuse it imo).
The multiple branching paths sound like a nice idea, but were executed in such a way that it was so easy to get lost and end up in big circle.
The second stage, the manor, was just terribad. Signs that point the wrong way, confusing layout, and possibly the most confusing Crecendo event ever.
There are a supreme lack of lights in the second and third stages. As Chet said, there's just too much darkness without any breaks. Combined with poor direction and hectic horde attacks, it can get really nasty really easily, and you really start to feel fatigued.
It looked nice, but I did'nt really have much fun until we got to the fourth stage. Which also turned out to be really short
3/5 Stars