I'm honestly shocked by so many positive reviews, but glad you all must have had a different experience than us.
We watched all of the videos on youtube and were super excited for the experience so we bought our tickets in advance (Definitely print them out, a lot of people had problems scanning from their phones)
We went last night (A Wednesday) and parking at the zoo was easy/plentiful and our shuttle driver was funny and friendly. Lines weren't bad at all (assuming mid week/7:30 time slot helped with that)
Once we got inside, the "clown" in the waiting area was awkward at best, we were way more interested in the video playing in the ticket line outside.
Once inside Scarehouse, the decorations were pretty cool and a few of the illusions were great, but the group behind us was sent in so soon after us that they caught up several different times, making us one megagroup of around 15.
I could hear that the woman in the front of our group was scared a few times, but by the time I (7th/last in line) got to those points the actors were either just standing aside or making half hearted attempts to get back into their hiding spots. I kept expecting to be followed by someone creepy or chased with a chainsaw, but honestly most of the actors didn't pay much attention to us at all. Especially once the groups merged and we became the middle of a way-too-big group.
The shuttle ride back was full of comments like "I can't believe I paid $40 to walk through a maze." and "We should have went to Kennywood"
As for the basement, we didn't want to risk another $30 each to try it out but from the screams we heard and the man running out wrapped in plastic wrap..it certainly seems that's the way to go if you're going to make a trip to The Scarehouse.