Ok, it's not thoroughly fair to label Thou Shall Not Kill...But Once as just another kung-fu movie as director Au Yeung-Jun does display fairly good storytelling competence and ambition to stand out in a very crowded room. First half definitely benefits more from this as the atmosphere ever so slightly feels fresh for the genre and it's a vehicle suitable for Chen Sing's range as an actor. Not that I would expect it but fact of the matter is, there existed an opportunity here to leave out much of the martial arts without consequence and it's also a fact that Au don't distinguish himself in any way when concentrating on the fighting. For the moments where it does try, albeit in a crude way, Thou Shall Not Kill ... But Once is worthy of respect.