Groove coaster on iOS is one of my favorite rhythm games that I have ever played. The music is enthralling and amazing, the charts are spectacularly designed, the avatars are cool, the games whole theme is completely innovative, and best of all, you get some great tracks for completely free! However, groove coaster best content lies in the purchasable packs, where you can find content unmatched in difficulty for all of the rhythm game masochists (like myself) to enjoy. However, this does require some price commitment from you, so I greatly recommend signing up for a taito ID. However, the price is a small penalty when what you get is so good. Songs like Satisfaction, Stronger, DX Choseinou Full Metal Shojo, and literally everything in the touhou and kagerou project sets make this a worthy pickup for any self-respecting rhythm game player