Actually, I didn't think the "mood changes" were bad. The changes are only sub-plots that, I felt, didn't detract from the film's main focus-revenge! Most of the film focuses on Joe and Fung's drive to find the bad guys, and I felt that the stuff about romance, etc, is there to give viewers a bit of a break. The romance played a crucial part in the end, anyways :)

Anyways, I enjoyed watching the film. I didn't like the beginning, which was a bit muddled and confusing, but apart from that, it's quite coherent. I loved the ending, with its touches of black comedy ("Here you go, now you can kill each other", "You want to kill him right? Now go for it!") and Stanley Fung puts in an interesting performance.