I wasn't excited for it, since several of my friends told me it was dull (and I wasn't a fan of "revenge a love story", a movie in which Juno Mak had a lot of saying). I really liked it. It was awesome to see Anthony Chan, Chin siu Ho, Chung Fat, Richard Ng, Billy Lau and Kara Hui in the same movie. I loved the throwbacks to Mr Vampire. That alone made it interesting to me. I also liked how the main character was actually the building, it reminded me of Kung Fu hustle in that regard.
Visually, it was beautiful, save for a few bad CGI. The atmosphere was simply incredible, and some visuals were haunting. It didn't feel like Mak was ripping off japanese horror, because he really used chinese folklore, so it was really its own beast.
The character arcs were interesting. The story as a whole, was actually quite good. Even the so called twist was well made. I mean, it did make sense, considering the main character's arc.
Action wise, it was light. The first fight wasn't that great. Chin Siu Ho doesn't remember how to throw a punch. Which is a pity. when you put someone like him against Chung Fat, the action should be amazing. The climax was way better on every account.
It was a great surprise to me. I only regret how little Richard Ng actually does, because he's awesome.