Lots of conspiracies and intrigues make for a gripping watch with very suspensful moments.
In season one, I didn't really get to know the characters enough. However, in season two, I was more emotionally invested. It is also even more gorey than season one, though - at one point I got a little sick. I'd say it is almost Game of Thrones level of gorey.

If you can't handle gore, don't watch it.

I'm still not a big fan of the OST. And the cliffhanger drove me crazy! Can't wait for season three.