Sometimes I wonder how this games survives, because it is such high-quality and extremely friendly with its monetization schemes. This is a game that you can fully enjoy without ever paying anything - you only pay if you want. Yet still it offers some really high-quality original songs and, specially, 100+ "cover" songs that are mostly famous anime songs, from the 90s (Rurouni Kenshin, Evangelion) to nowadays. Casual mobile games should be fun and this one certainly is, its Guitar Hero-like gameplay (with the fingers) is fluid and addictive. I'm currently spending a lot of money on this game not because I need, but because I think it deserves and I hope it doesn't end anytime soon.