It's not a bad film. The scripting, acting and all the rest are pretty darn good, as this is a film with some jumpy moments. It's tense all the way through, with some good ideas (someone vanishing from the off, a seemingly never-ending corn field and the bated breath moment when someone gets too close to the Scarecrow for comfort). Unfortunately it does contain two HUGE gaping plot holes. One is that a way to destroy the monster (or at least slow it down) is found fairly early on, except the person concerned seems to neglect to tell anyone about it and two, the ending....well, the ending is pretty bad all round. I have an issue with the fact that some people are given an escape route, but waste lots of time doing something which (because of the ending) seems to be pointless.
Why is one of the characters blessed with 'visions' except to let the audience know why this is happening? Why do two of the characters argue with a third who is quite clearly going off his head (however understandable)? The rest of us are shouting at the screen at this point, "Don't listen to him". The others should have taken control.
Personally, I'd say don't buy this film. Rent it, when it gets cheaper, or with any luck it'll get shown on the telly soon. One to be enjoyed late at night with some beers and popcorn.