While I don't hate this game, I find that it's much weaker than the first game. There's a three day gimmick while interesting the first time around, is just a weird barrier that ultimately doesn't mean anything, since you can just skip through it by holding space down in the main menu. On the one route I've played, I played along with the gimmick, and it just felt bizarre having to wait, though I will admit that there was quite a bit of anticipation between the second and third day, so if that was the objective, then I suppose it was done well enough.
There are a few quirks that are quite annoying - for instance, for some reason you're unable to just smoothly scroll down a page, it has to pause every few seconds. I'm unsure if this was an intentional design decision or not, but relative to the first game where everything felt a lot more smooth and responsive, it's quite annoying. Another thing I disliked is how you obtain the data this time around. Instead of talking with your AI companions and having them slowly reveal the story to you, you instead just select and choose which entries you want to read. Furthermore, the AI companions aren't essential to the plot of this game, and feel more like side kicks than anything else.
That being said, the AI sidekicks in this game aren't bad, and in fact, it's interesting to hear their thoughts on the going-ons of what occurred on the ship a few hundred years ago. They inject a bit of light heartedness into what is ultimately a tragic story, though *Mute's route definitely has some even darker themes on the third day. I can't speak for Hyun-ae's route, since I never did get around to doing her route, but I'm positive the third day with her won't have nearly the same impact that Mute's did.
And that is one of my big problems - this is subjective of course, others may loved it - but the ending to Mute's route is quite dark, as mentioned before. It deals with some really serious issues, and while it was quite effective, and it hit me like a bus, I didn't particularly care for it.
Overall, only buy this if you're a HUGE fan of the original like I was, but make sure to avoid Mute's route until you finished Hyun-ae's, otherwise it'll probably sour your experience.