Now the reason this works for other films for example Scary Movie is that the film they are pariodying in the first place isn't ment to be funny, so that works but it doesn't with Epic Movie.
And why EPIC! I mean its not that epic to be honest and the storyline is all over that place, for example (this may contain spoliers - not that you would care anyway)
Epic Movie starts off with these 4 orphans, these 4 orphans are related at the start to other movies, like X-men, and...urmm, I can't think of the others.
But anywa, they all get these charlie and the chocolate factory style gold tickets, still.. not... very... funny. So they all meet up at the factory, and doing the worst Michael Jackson impression ever, they like most crap american comedies, end up with half nacked girls nocking peoples balls out... still... not... funny.
So they get locked up by the bad Michael Jackson impressionist, and they suddenly find a Narnia like wardrobe, and of course they end up in narnia, and they bring in jonny depp as captin jack, and stuff and yehhh. It's all *@$% from there.
Then they parodie click, (the movie with the magic remote control) and they all do stuff.
Don't spend £6 on tickets, don't watch it... its crap. Period.