It plays like a mouse maze game.
the heart lags behind your mouse alot (atleast on webgl) and that can be fun to play, as you have to plan ahead for the heart to catch up with you.
the thing is though, you don't seem to be diving deeper anywhere.
As for the audio, I liked it, it's relaxing, but it lacks sound effects.
Just have to say, really underrated entry here. It's a nice relaxing game