Good directing, weak plot The general idea is good, and it's very well directed.
It starts pretty boring, but picks up the pace around 0:30.
Now the bad news. The ending reveals several massive plot holes, and is also a bit underwhelming. When I see "twist" in the description and reviews, I expect it to be bold and unexpected. When the whole movie swings your guesswork between "option A" and "option B", you want the twist to be "option C". Sadly, that's not the case.
I'm not disappointed in the ending itself, I'm disappointed because this movie could really be so much better.