Well, you get the idea from some of the other reviews, but if anyone is considering seeing this, the only possible justification is to see what might be the worst film of all time. The trouble is that it's supposed to be a comedy. Seeing a horror film or a melodrama that is unintentionally funny is one thing. That can be enjoyable. Seeing a comedy that isn't funny AT ALL is something different. There is no pleasure whatsoever that can be gained from watching this, unless you are the sort of person who giggles watching paint dry.
Don't get the idea that I don't enjoy spoofs. Airplane!, Young Frankenstein, The Naked Gun, even the original Scary Movie (some of whose writers - though obviously not the more talented ones - came up with this dross) were all great. This, however, isn't. Having someone look like Owen Wilson or Napoleon Dynamite is not in itself funny...you have to go further and actually have them DO something comical: that's what a spoof is supposed to be. As for the film's one potentially good gag - redoing a well-known romantic comedy scene with the male and female roles reversed - well, that could work once. Here, the writers try it several million times.
Humour is a very individual thing, but anyone finding this funny should let psychologists run a few experiments on them: they are clearly deeply unusual people.
That said, I hear Epic Movie is even worse.