So I know I said I was going to quit Hatsune Miku, but looking at the trophy guide made me realize it should be a fairly easy game. I just assumed I'd have to get good scores on all the songs, but I guess you just have to pass them. Might give it another go.
Have you played a rhythm game on the display that you're using before? If there is input lag that can ruin your ability to play successfully. Make sure you check the calibration settings if you haven't.