I'm giving this game three stars for its general playability, although I'm not too fond of the time limit on answering questions. I also like that it adjusts the level of the next question to your success answering the current question.
What I'm not enjoying, is the truly trivial nature of the questions. Yeah, I know it's a "trivia" game. But the sports, music, miscellaneous, and arts questions all seem to involve contemporary pop culture that I'm simply not in touch with. My experience so far is that the "easy" questions involve things you would have learned in high school or college that could be considered relatively important in the grand scheme of things (science history literature) whereas the "hard" questions involve ephemeral, contemporary, silly knowledge like hit songs or basketball players. I guess the developers show faith in our education system by structuring things this way. I infer that they believe, "Hey, you went to school, asking you about Charles Martel is easy peazy!" But it's just not worth my time to keep running into "hard" questions that are beyond my ken because I don't have a 16-year-old's taste in music and I'm not a sports fanatic.