Why so much hype?

Clever, believable, and super fun to watch. It totally has replay value.

As somebody who had not heard any of this before, it became a curious phenomenon to sit and watch a film and slowly have the realities begin to click into place.

It's funny, it's tense, it features two great performances from two actors and the director expertly creates a web of odd tension where you actually don't know what is happening for the majority of the run time.