There's a natural authenticity to the film that makes it intensely watchable, even though it's repetitive and slightly underwritten. Several characters just refuse to speak, leaving infuriating gaps in the story and dialog, which lead to misunderstandings and more serious problems. (Does anyone really behave like this outside the movies?) Where it works best is in the desperate central characters, nicely played by young actors who effortlessly highlight the contrast between the hardworking, single-minded, seriously intimidated outsider Guei and the more sophisticated, pushy, devious Jian. The side characters fare less well; they're underdefined and mainly there for symbolic or plot-spurring purposes only. But the feel of the city is terrific--colourful and vibrant, heaving with bicycles and yet finely focussed on this specific one upon which so much depends.