The keywords already tell you the story outline, so I skip that.
Most of this movie is fan service - a lot of (female) Max Payne (the real one, not the awkward 2008 dud); of Agent 47, a bit of John Wick, a nod to Leon ("all of them")... not too a complicated story, well-choreographed and filmed violence, nice modern Japanese atmosphere: I got what I expected, a satisfying action flick. And that's probably what Netflix ordered for us, "Because You Watched".
But what made it really worth seeing this movie for me were a couple of minutes of actual acting. Winstead is great at her Terminator/MaxPayne/Leon/Wick/McClane-Show, and when she's allowed to act, she proves worth being the lead. But when Jun Kunimura turns up, he expresses so much in a little time, that was what really sold this movie to me. (Also, solid supporting performances. Kudos.)
Overall: not as bad as critics say. Stylish Entertainment.