With a rating of 4.5, I expected something groundbreaking. What I got was an above-average story with below-average drawings. The ost was indeed amazing and perfectly set the mood for every new story. I personally would have preferred it to end after Door 4 maybe 5. The last 3 doors kind of dragged themself and I just wanted to be done with it, the first 3 doors were amazing on the other hand.
Overall it may be an amazing visual novel, I can't decide that since it's pretty much my first vn, but if you are looking for a good game because of the rating you are at the wrong address. You will be reading corny dialogues for at least 35 hours straight.