If you've seen a lot of ghost movies you certainly won't find this as scary as some reviews are claiming

Rating: 4/10 (16 July 2011)

After all the hype I was pretty keen to see Insidious. It seemed right up my alley; supernatural movies are my favorite subgenre of horror and I actively seek them out, from the mainstream right through the low-budget indies. But ultimately Insidious was a disappointment.
Most people who didn't enjoy the movie cite that the third act borders on absurd. While that's partially true (there were actually points where I felt like the protagonist was being attacked by The Crow and Darth Maul, and the explanation is a bit of a stretch) that's not the reason the movie didn't work for me.
The reason it didn't work for me is that everything about it was "overcooked". Even the opening credits, which could have been understated and dread-inducing, were diminished by CGI effects. It pulled out all the good old tropes that us ghost movie fans look for - the kids drawings, the creepy tune on the gramophone, the gentle buildup of sinister events etc. - but in each case it was just handled too heavily, too evidently, too gaudily to sustain the foreboding atmosphere that drives the best of these types of movies.
The only two genuinely creepy scenes were already revealed in the trailer and everything else unfortunately served to detract from those moments by being so heavy handed. It begins by masquerading as a ghost movie for adults, but don't buy into it... by the third act you'll probably agree that this was clearly targeted at a younger, dare I say it, sure I dare - ADD - generation.
I see what James Wan was trying to do with Insidious, I really do - it was a brave attempt to update Poltergeist for a new generation - but now I realize it takes someone with a finer touch than him to pull off a feat that big.