It has good deal of mystery and the plot is pretty interesting. It is not as much of a masterpiece as steins gate, but it is still well done. Depending on your psyche, it can also be a bit scary, and there were times I got chills from some scenes. However, the protagonist is fairly unlikeable.. He often gets into panic attacks, he is secluded from the society, has very few friends, avoids contact with other people, etc.
I mean imagine an Otaku, and take it to ridiculously extremele levels.
At any rate I would heartily reccomend it.