Two characters are shown passionately making out. One character sounds like he's moaning when singing.

Every character is killed one by one, actually only one survives. A severed limb is shown twice. A severed foot is shown once. A sledgehammer is used to bash someone's face, some gore. One face is actually completely unrecognizable and just a mass of gore. Rocks are shown at a certain character and does cause bleeding. A lot of deaths are just abrupt, but hey, at least the killer lets them finish their song before killing them.

About 34 f-words. Prick and asshole are other words used at least once.

Characters smoke at the camp fire at several points. One character passes weed onto another, but the weed is quickly disposed of before it used.

The eerie music may frighten some. The abrupt deaths (occurring right after they're done singing) may frighten some. Perhaps the idea of everyone being slaughtered one by one in some gruesome manner in the woods may frighten some. Hence the name, Don't Go in the Woods.