Umineko began as a second set of sound novels by the same producers as Higurashi. It will eventually also run for 8 parts, the 6th of which was only just released in Japan a couple of weeks ago. The anime which I just finished watching covers the first four arcs, and will almost certainly contain a second season to be released in a year or two when the sound novels wrap up. Because of the incomplete nature of the plot, it's hard to know how critical I can really be about Umineko. For all I know, this story will also resolve into something amazingly intricate and satisfying.
What I do know is that I don't like Umineko nearly as much as Higurashi, just comparing their first seasons. While Higurashi made you want to 'turn the page' for more at every episode's end, I felt far more ambivalent about Umineko. Here's the basic plot. A rich family has gathered on an island to discuss the imminent death and inheritance of the family's patriarch. Legend tells it that he rebuilt the family's fortunes from near bankruptcy, supported in large part by a slush fund of 10 tons of gold bullion. The family folklore is that this gold was provided by a witch named Beatrice, though most dismiss the supernatural elements and believe Beatrice, if she even existed, was a mistress at best. Along with the gold, whose location is unknown, there is a family epitaph which contains a riddle which it's said when solved will lead to the gold and open the door to 'golden land'. The epitaph also contains disturbing verses about a huge heaping load of sacrifices, people being killed and the ressurrection of the witch.
I'll give you three guesses what starts happening and the first two don't count.
Those of you who guessed a bloody mess get a gold star. Members of the family start dying, many in ways apparently so disturbing that not even japanese tv will show it. Parts of many of the bodies were pixelated because of the gore factor. Not that I was able to see it due to the pixelation but at one point people had their intestines explosively disemboweled and then their body cavities were either stuffed with candy or cookies, depending on the translation. Happy Halloween.
All of this is merely incidental though. The deaths of the family members act as moves on a chessboard between the main character Battler and the witch Beatrice, who are locked in a ideological curb-stomp battle over whether witches/magic exist. The family goes through groundhog day looks where different murder scenarios take place, many of which carried out by demons, magical girls from Purgatory who don't wear pants, magic, etc. Battler then has the ridiculous job of denying that magic was involved. He has to argue that there was a perfectly mundane cause for all of the murders, many of which end up as closed-room murder mysteries a la classic detective tales. Considering he's exists in a meta-universe looking down on these scenarios and is in an endless groundhog day loop until he either wins or loses, he must be suffering some ridiculous amounts of cognitive dissonance. I don't believe in magic, especially not this magic which is putting me through these repeating days of murder and mayhem.
There are a crapload of different witches tossed in to boot and all of them have various crazy servants who mostly run around killing people. The goals of each witch are opaque to say the least and you're not sure who's good, who's evil, or even which side each of them is on because they're all capricious as hell and a good chunk might be insane.
A lot of how I end up feeling about Umineko will depend on how well the Gordian knot unravels I think. Right now, it's a tangled mess and the whole 'I don't believe in magic' part is growing a little thin. If I were Battler, I'd be hiding behind Clarke's Third Law for all I was worth. Either that or using the 'It's just a coma/dream' defense.