This was an interesting story, definitely personal/psychological horror. I don't think I really liked it, though. I felt like it took too long to get where we were going, and then when we got there, Samnang gets into a kickball game with a head and then rips his own face off. I don't know... I guess it just didn't work for me.
The kids were creepy, but was their enjoyment of Samnang's death really a necessary point?
Also, the fact that Samnang likes to have sex with young men/boys, I feel, didn't really increase the story at all.