I'm a bit surprised at all the strong negative reactions.
Just saw this for the first time and enjoyed it quite a bit. I thought the idea of applying typical film noir script/dialogue to a different setting was fresh and original. For those who can't get past the "unrealistic dialogue", I have to ask, how do you feel about film noir typically? I hate to break this to you, but people didn't really speak like that in the 40's and 50's...not even detectives. It's an entirely fabricated film genre, always has been.
It's not unusual for a Shakespearean play to be shown in a modern or otherwise anachronistic setting. People don't complain about that ruining the realism of Shakespeare. That would be missing the point. For a presentation like that (or this) it's just part of the formula.