This film can have different names: Ngai sing (the original Cantonese name), Call of heroes (international release name), or Wei cheng (Mandarin reading of the title characters which means "Dangerous town").
Summo-hung directed fighting choreography here, but I find to like his recent years' works less and less. He uses too much of wires and makes fighting scenes ridiculously supernatural or superhuman. Fighters do unreal flips in the air and possess strength of superhuman monsters. Everything is exaggerated and it doesn't do good for this kind of movies about seemingly normal people. I could understand fantastic moves and techniques in a film about super-heroes, but not about usual martial arts practitioners.
Many fighting scenes were shot under different angles and then edited to look terribly with constant camera jumps from one point of a scene to another making it very hard to appreciate a fight itself.
What is good in this movie is that the plot takes really unexpected turns. Unfortunately it's very predictable afterwards and once you've met those interesting twists in the story you won't meet any more of them.
I noticed a blooper, there may be more, it's just that this one was very obvious. One of the main characters naps in a chair waiting for a barber and he is wearing a pair of shoes of a particular design. In the next frame his shoes are different!