I'm not quite sure how to classify this other than Adventure, but traversing the world is not unlike a Paper Mario. There is no real combat, but you can sing; choosing a direction chooses both the note and the color. You'll occasionally get little prompts with colors or directions (often both), and if you sing those notes in that order, a thing will happen. You travel the world, singing to solve puzzles, mostly, but also to stop the world from ending. Each chapter has the same basic groundwork, but also new mechanics and dressing, so it keeps things interesting, but consistent. Some of the puzzles are a little obtuse, but it's neat that it doesn't just bog you down with unnecessarily detailed explanations of obvious things, so the tradeoff isn't so bad. It's definitely not a hard game; something you play more for the experience than anything.
And what an experience! I'll be up front: there's a lot of "magic of love and friendship" stuff going on, so it's a little hokey at times, but if you can swallow a bit of wholesome sugar, you'll find some genuinely great moments. This is the story of a legendary hero chosen by the goddess, Eya... and it's not you; that is made readily apparent from the very beginning. It's kind of funny that only the hero gets the achievements, too; you have nothing to do with them, because it isn't your story. All the same, no matter what kinds of adventures make you tick, you're likely to find something to enjoy here; my favorite was Act 3, but each act is unique enough with its gimmick. The game is unique with its visuals, too; the colors are bright and bold, making beautiful, borderline-surreal landscapes that I just couldn't get enough of seeing. There is a small, distinct rhythm game at the end of each act, which takes place in a not-so-borderline-surreal scene that I really liked, too. Most of all, despite its starry-eyed delivery, the actual message of the overall experience is a very good one.