This is quite a fun concept, and I think it's excecuted fairly well.
The controls are a little too slippery for my tastes, and I often found that I would move away from an enemy, only to be unable to slow down enough to avoid another one. The sprites make it obvious where you should hit an enemy to score the most points, but I also found that simply going up and to the right makes it so that enemies can't catch up to you, and thus your score could become infinite with enough patience ;)
All in all this is a fun experience that would take quite a bit of skill to master, yet can still be played if you're an amateur like myself :)