The visuals are absolutely stunning. You don't see a game with such a striking, visual style that is so well put together every day.
The dream-pop soundtrack is pretty decent. Most of the time it sounds like a version of grimes that is way less uncomfortable to listen to.

The game has a very short runtime and can get somewhat repetitive at some points.
Most of the time the controls are janky and therefore don't justify the sometimes awkwardly placed obstacles.
The game does not do a very good job at matching the quick time events with the music.
The story of the game made little to no sense to me, but I reckon that this is not the main part of the game.

But my biggest complaint about Wild Hearts is the fact that after each level, you get sent back to the level selection. It would have been a much better idea to just let the levels run through, especially because of its core concept of the pop album that accompanies the game, which is constantly interrupted this way...

I wouldn't recommend buying this game. Instead, watch a playthrough to experience the music as well as the visuals. The gameplay is not that important.