I've seen hundreds of horror movies in my lifetime. This rates among one of the least entertaining or scary.
None of the characters were convincing or engaging, in fact I prayed for their deaths after about 15 minutes. The plot was nigh on skull-numbingly poor and the scares relied almost totally on sound effects and offered precious little on the visual front.
In its favour, the plot was not entirely predictable, but I was left not really caring what happened less than a third of the way through.
The thin pretext of a 'shroom'ing holiday could have quite easily been left out and all of the visions etc. could have been explained by a dodgy smell in the air...
Anyway, don't bother wasting your time with this one. Have a nice cup of tea instead and do something constructive...