Each of these groups has something special that allows them to stay in the game. Skills, intelligence, dedication, luck. What happens a lot here is that a character has triggered a major event without even knowing it. It's definitely similar to Arrested Development's style of humor, where different groups of people, each having an agenda of their own, cross each other's paths.
The humor: It's VERY funny. But you have to be a native Chinese speaker. There are different dialects. Taiwan people speak the Mandarin but the accent is different. You can't possibly understand the oral expressions and appreciate the nuances if you haven't spent a significant amount of time living in China.
The characters are mostly male. Everyone is going after something, often using the wrong method. A good metaphor of life, where we try to achieve something but actually are ruining it. It's entirely plot-driven, not character-driven.
The special effects: Really good. They are unnecessary to the plot, which shows that the director is willing to spend lots of money making the movie look great, to try to get people to watch. Indeed, a movie needs to succeed in all departments to be considered a classic, and this one does.
Who shouldn't watch this movie: it's significantly more fast-paced than other Chinese movies. It's much faster and denser than Infernal Affairs 3, for example. It's intended for a quick-thinking audience. Other people won't even be able to follow the plot, and won't enjoy it.
