Hello fellow surfer!
Very nice try! I liked the combination of the beat with the sleek movement.
I read the description and you mentioned a part "There's not much more", and I felt a discouraging tone. There are ways to add more with little work. For example, you could have a coin counter, and for every X coins to increase the surfer's speed. Or unlock an ability that makes him immune for the next hit. So, next time, when you feel that the game need something "more", try to think of something simple to implement, like the example I mentioned above.