It is not for kids, except maybe the ones who never grew up (like myself). If you enjoy pointless humour, humour aimed at violence, humour aimed at sex, etc., then you may enjoy it. To date, as far as I know, there is only the pilot. I love it and wish they would make more, but I would not allow anyone under 17 to watch it, and would not allow my own children under 17 to watch it without me there to guide and explain. And even then, they would have to be 16 at the minimum.
The full pilot can be found on youtube.
The artwork is gritty, as it is intended to be. The humour is as blunt as korgoths personality. Most of the humour comes from the side characters and the antagonist of the episode, but Korgoth himself provides some, albeit very little but still funny.
There is an exceeding amount of violence, as there would be in a post-apocalyptic world that has been reduced to an iron age or medieval age. There is a veritable lot of sexual enuendos, and it is highly sexist and demeaning toward women. There is some cursing, as most cartoons on Adult swim seem to have, but not bad enough to be censored (Which is better than I can say for some of the more mainstream prime time cartoons not aimed at children. To be honest, I am surprised at the few times The Simpsons has had to have words censored. The "shock&awe" of Korgoth is due more to its writing and plot thatn having to rely on cursing). There are scenes involving the imbibing of alcahol. Both in the tavern scene and in the scene where Korgoth meets a shady bad guy (the kind who has a lair and henchmen) named Gog Magog (which Korgoth hints at blatently as having met before or having prior aquaintance with).
All in all, not much worse than Heavy Metal: the movie, but with less actual nudity. And what nudity exists in the pilot is definitely not attractive.