You should watch it.
I watched it without expecting much, I've seen a lot of "horror comedies" you might call them and this was one of the better ones in my opinion. I saw some hate on it on these boards, and I thought I'd share my opinion on it.
If you want something with a good story, it's not a movie for you. But if you like this genre then I think it won't disappoint you. This movie is probably 7 stars but i gave it an 8 because Mackenzie Davis (it's my first time seeing her in a movie and I liked her). Also the main guy Dag (i think) wasn't that bad.
What I didn't like about this movie is some things are joked about too often, like in the situations that you wouldn't want them to (that's just my opinion though). For example if you compare it to Shaun of the dead (zombie horror comedy) which I thought was pretty fun. This movie goes to the extremes to try to be funny. It works couple of times but the rest doesn't add much to the quality.
8 star is pretty good rating but I think it kind of deserves it, if just for the fact it has 5-6 stars at the moment.
And as always, don't listen to movie critics before watching it yourself :)