keeveek: You may read the news thread about the release.
A LOT of people were screaming "GOG released pedo-porn anime game!!!!!!" without even knowing what game it is.
I've played a lot of visual novels and many of them include romance. Some of them include sex scenes (not always with 18+ content). I can imagine the drama if one of those nutjobs found out there are teenagers having sex in a game.
I love visual novels. I'd buy some of them, but unfortunately, many of the great ones came with Japanese language only.
It's not that simple I think, GOG probably wouldn't be able to put games with that type of sexual content content (even drawn/animated type) without some kind of change in legal status of this store, or having an 18+ Adults section of the GOG site, which would naturally result in a damage of reputation with many viewing GOG as a Criterion Collection of sorts for old games, having eroges here would turn some people off.
Also, as someone who used to play lots of translated VN a few years ago, there's almost no division in the sexual content, there's no "softcore" VN's (afaik) where the sex is more like the type you'd see in a Hollywood movie, it's always either 1) No erotic content at all, or 2) the sexual content is pornographic, showing genitals and everything else.
But on the topic, have you played this VN:
http://en.wikipedia.org/wiki/Tsukihime It's my personal favorite, and is pretty much unlike any other VN I've played, it has a really unorthodox and "serious" in tone storyline with plot twists which are almost impossible to predict.