If you watch it again you'll notice that the "self awareness" and "stilted" performances you refer to are only aparent in the first half of the film because its conveyed - in my opinion - as a dream. Watch again and you'll notice that in the second half the script and performances change as does the reality of the film.
jeez, You sound lke Mark " Commode " the film critic on Radio 5,I call him Commode because he's so full of ***t !
Either it's a good film or it's not no need for all the crap he spouts