I'm not sure what to make of this movie. It's not a long film, and so repeat viewings may make people appreciate its intricacies more. The film revolves around a small tight-knit group of assassins who work by killing their victims in ways that would appear to have been purely an accident, the "accident" being decidedly gruesome once executed.
Led diligently by a straight-forward highly intelligent man they call "Brains", they work to ensure no trace can lead the deaths to themselves. When the tables are turned and a member is killed, the focus closes on "Brain" who struggles to find out what has happened and gone wrong, and who is out to get them.
It's a moody film and uses the claustrophobic HK atmosphere well. One problem is that it's hard to decipher all that is happening from one viewing. It can get ponderous and confusing. The acting is generally very good and the action of the deaths very well done, but it doesn't compensate for the lack of clarity. Then again maybe it wasn't meant to be a tidy film and that is the point.
Overall, I thought it was okay and interesting enough. Maybe with some more work and time on the script then it could have become far better. Not bad, but just not great.