Story: The concept of dream and dream demons was very interesting. I liked the idea and adding a cute heroine definitely made things better. However, it just didn't deliver as well as I would have liked. They had a good thing going but the ending felt so complete. They added all these undeveloped bits that I wonder why they added them in the first. What was the point of mentioning the romance or introducing certain ideas if they won't be carried out? The ending was mediocre at best leaving many unanswered questions. It had good ideas and theme along with some cuteness and humour but that wasn't enough. The series is short and is easy to go through so it didn't feel like a complete waste of time. However, it was definitely disappointing.
Animation: It was alright. The character designs were all pretty and attractive; however, Merry was the only memorable one. The real world was nicely animated but the dream world fell short to me. The dream world were lackluster and bland when it could have been much more. The action scenes were disappointing as they were very choppy. However, for the most part, the animation was pretty and they gave enough fan service without being ecchi or overdoing it.
Sound: I really liked the opening. I actually liked the opening more than the series itself. However, the rest of the music was subpar. The soundtrack varied from generic gamer music to woodwinds. Although it wasn't bad, it was strange. The ending was ok and catchy but generic. I probably won't remember it in a while. The seiyuus did a good job though,
Characters: Good ideas without enough to flesh them out. Like the plot, they started out well but didn't have adequete development or background. There were parts of them that were introduced but were never fully explained. However, for the most part, they were cute and likable.
Overall: Good idea but disappointing. It will start out fun but leaving you unsatisfied. Really cute heroine though.