There are no light sources. It's just bright everywhere. I don't think it will play very well. I've put it up on the beta server, so you can give it a try, though.
We played a basic version, it was very fun.
As for light sources, I tried using normal lights, they failed, so I tried sky, still looks like over bright. There aren't any leaks either, no errors.
Making b2, as spawnfix