I am going to state right away that I have played the PS Vita Var Commons version of the visual novel, and have nearly 100% the whole game.
Now as someone who is a fan of the game, I would not reccommend this anime.
I'll start with the story. And yes I will be comparing it to the game as that's what I knew first.
It starts off with Koharu being told about the ship called NORN, and that she must board it to pretty much be useful and not be alone anymore. It's obviously the end of Winter, as everything is covered in snow, with bits of greenery trying to poke out. So it's telling us, like the traveler told Koharu, that spring is when the ship will come and that is when the story will truly start.
And it does come but they go aboard a small ship first to get to the big one, while Kakeru has her wrapped in ivy and Akito is off doing who knows what while eating an apple. Cause that makes it totally look like he was searching...
In the Visual Novel the whole ship touches down. And instead of Akito and Kakeru searching per se for Koharu, Koharu and Sorata find the ship and then get jumped by the two boys investigating the landing. Needless to say Sorata was not there, nor did they get jumped. He just kind of appears, on the ship, instead of in town. Cause that makes sense.
I'm giving the story a low rating because of the changes. Where they could be taken as good, it seems more to me they didn't do a whole lot of research into the game aside from the few snippits of information on it's Wikia page.
Example: Koharu uses her power in the anime right away, despite hating it. In the game she waits much longer before. Yes I understand they put her into a position for that to happen but her original character wasn't naive enough to run around the ship when told it's dangerous.
Lets move onto animation. Now a lot of it is very pretty and good, but there are a few moments where it looks a bit choppy, or it's missing frames while other parts seem to have too many. now I'm not going to be to critical on this part as I know some of the stuff Japanese Animators have to go through, especially when they have to release an episode weekly without being allowed to push dates around. So overall it's pretty, but I prefer the scenery and effects more than the characters.
Sound, kind of self explanitory. So far all the Voice Actors seem to be true to the Game, which makes it more enjoyable for those that have played it, but I feel like some of it could be better? Like there isn't an overjoy for the VA's to come back and do the same characters.
Speaking of which, the Characters. I'm kind of rushing the end part of this as story was my biggest issue but the characters seem off as well. Koharu is more naive then she originally was. Her character in the game I took as quiet, a bit clumsy, and slightly naive, but not completely to the point she wouldn't listen to someone. She isn't an overly pushy character, but she is very caring and gets concerned about others more than herself. Also a lot of her naiveness is from lack of knowledge, she grew up kinda being isolated so makes sense not to know a lot of common things but she also knows how to listen to people and not just let it go in one ear and out the other.
The other characters are a bit off as well, Akito is kind of mellowed down [He is terrified of Hiyoko's where the anime he is only slightly scared of them], Senri isn't as quiet or complainy about what Kakeru does, he just kind of accepts it somehow.
Another issue is the ship itself, they made it a lot more technologically advanced then the game made it seem. And the locations of say the rooms, dining hall and meeting room are all different. I don't understand why they felt the need to when some perfectly good designs already existed for it that aren't to complicated. I guess for the fact of wanting it to be fancier would be a better explenation but the ship itself was never complicated, and it seemed easy to navigate.