This Hong Kong action/Sci-Fi movie did have potential, and the synopsis did seem appealing, but the movie ultimately failed to live up to the expectations. And as for being a Benny Chan movie, then the movie just didn't really live up to his usual quality productions.
First of all, I want to address the title of the movie, the English title is "Assassin: City Under Siege". What? This movie title is probably as far as they could get from the actual storyline and what the movie was about. So don't put too much into the movie title, as it is a hoax.
The storyline was adequate, although it tended to be rather cheesy at times, leaning too much up against Marvel products, bordering on being a blatant rip-off at times. And that is what the movie suffered from the most. It was sort of a Hong Kong version of "X-Men", just on a toned down scale and a less funded scale.
As for the people on the cast list, well I can't claim to be much fan of Aaron Kwok, and his performance in this movie didn't really win me over this time either. Shu Qi was the one who carried the movie for me, despite not having the lead role. And also Collin Chou, who usually does put on good performances and good action, really didn't impress in this movie either - as if his heart, wasn't fully in it.
Effect-wise, then "Assassin: City Under Siege" (I just love this title) was actually quite good. The CGI worked out well, and the action sequences were nice as well. Despite this being martial arts with wires, then the fighting worked out well enough.
For a Hong Kong action movie, then "Assassin: City Under Siege" was not in the usual league of action movies to come from here; there are far better action movies available even the older ones with Chow Yun Fat.
"Assassin: City Under Siege" is good enough entertainment for a lazy afternoon if you have nothing else to do, just don't expect to be blown away.
