When it comes to stylish music-based games, I believe Rhythm Heaven is the best in its class. Not just because of its charming 2D animation work and art direction, but because of its uniqueness in sound design and its simplicity in gameplay. Sound cues play a brilliant role in the franchise, mostly blending so well with the track that it's easy to remember them. Rhythm Heaven is one of those rare games that, if you learn every cue, it's easy to play with your ears alone.

Melatonin fails at this, unfortunately.
Don't get me wrong, as an obvious inspiration of the Rhythm Heaven series, I personally think this game nails the art direction that made its source so notable. The lo-fi music may not be desired by some, but I thought it worked well with the overall tone.
As mentioned though, Melatonin falls flat in its sound design, specifically with cues. It can be frustrating to play this at times, because most of these noises are either indistinguishable from each other, or they are so faint that they almost don't seem there at all. Having this game rely more solely on visual cues is fine, but again it can throw the player off with split-second reactions.

This is a fine indie-developed music games especially for those who love lo-fi tracks. However, if you're looking for a match to Rhythm Heaven, and one that runs you a handful of hours, you'll likely want to turn elsewhere.