Yeah, "happy" or "fun" are not generally words used to describe Higurashi. Imagine the "Endless Eight" chapter of Haruhi as a disturbing paranormal/psychological horror-thriller. A bunch of schoolkids in a tiny, isolated Japanese village are unknowingly stuck in a time loop, repeating a June in 1983 when one or more of them devolve into paranoid psychopaths for one reason or another and start killing their close friends and others in brutal fashion. You, as the audience, are totally lost trying to figure out what the heck's going on in each time loop, whether there's a rational or supernatural explanation for everything, and how the different time loops connect/affect each other.
Since everything makes perfect sense in the end, and since the whole thing's pretty gripping, and even fun, if you can suspend your reluctance to watch violence enacted upon younger characters, I'd say it's a really great, original, clever series.