I'm a librarian who loves anime, manga, and reading a wide variety of genres.
Oof. The anime and book have the same pacing problems, but they're much more noticeable in the book, at least for me. Nothing much has happened, and there's nothing you could really call a plot. Also, in both the anime and the book it bugs me that no one thinks much about their life before everything changed. Akatsuki and Shiroe were college students with terrible social skills, and Naotsugu had a job somewhere. That's it, that's all I know about their lives outside the game.