Actually it starts off really well. The virus is suitably chilling and the way that the story of Sleeping Beauty is weaved in to the characters being frozen, maybe for a hundred years, is all quite intriguing. When Kasumi, a young girl selected to be one of the survivors, wakes up things really kick off and I was thinking that this could well be an anime to buy and add to my collection. Many questions are raised during this first part: is it all a dream, what has it all got to do with a game that a little boy is playing, and has the shady corporation created the virus for its own evil ends? All questions that initially kept me engaged.
The traditional 2D animation is gorgeous and almost worth watching for that alone. There's something about watching a new anime on shiny blu-ray. Everything is so crisp and fluid. Then we get to the abomination that is the CGI animation. Now, I happen to think that CGI can work really well within anime; just look at Oblivion Island, Appleseed: Ex Machina or Vexille. But here it's terrible. It looks like it's running at a frame rate of 12 frames per second; it's all so jerky. This completely trashes the quality feel generated by the 2D work.
The best thing about King of Thorn has to be Marco Owen, a prisoner who is chosen for the project. He's massive and charges about punching and shooting stuff. And he says his name a lot. Things generally pick up when he gets into some action.
If you like this you could also try:
Origin: Spirits of the Past, Princess Mononoke.