Seeing Yau Nai Hoi's directorial debut was a treat as it's one of the best HK movies I've seen in recent times. Nothing else, aside Johnnie To's other movies, come really close in terms of innovation, uniqueness and entertainment. The main attraction of the movie, though using a clichéd plot, is how the cops and the criminals communicate with each other non-verbally and unaware of each other in order to expose each of the sides' acts and how things progress through that, and for that reason it's easy to dub the movie as a high technological movie for it's own good (some people go far as calling it Hong Kong's answer to ENEMY OF THE STATE, which is ridiculous as there aren't any huge similarities whatsoever between the movies).

As you can already tell, I'm hugely impressed but I wouldn't consider the movie flawless. A minor flaw is evident in the story and it disturbs the consistence of how it first started; which is how the whole situation suddenly changed during the second half and how the character development went along by then. Yau did a great job keeping the first half of the movie on just focusing on the cops and the criminals and maintaining it during the closing reels, all while injecting an entirely new situation that I think would've worked much better in an own story. I wasn't bothered by this the first time though but after few repeated viewings, this actually had me thinking alot. For a minute I thought what it would have been if the movie was without any of these complications and twists that we see in almost everything these days; a story simplified enough, not too complicated and just going with the flow and take the build-up where it leads to... But like I said, this is only a minor flaw or nitpick so it doesn't affect anything at all for me.