I like the idea of flinging a flail around, but the game didn't feel like it did what I wanted it to. Sometimes the flail would lose all it's momentum at once, and sometimes it wouldn't gain speed at all. When I could spin it around, it was quite fun, and I enjoyed how fast it would go! Adding screenshake when you hit pretty much anything would probably help out a ton, and adding that onto the fun-ness that already exists with hitting things would make the game a whole lot better!
Easily a five star on the audio design.
Good luck with any future games you make!