The controls make sense and function well, but there's no visual style and nothing is challenging as long as you go at a moderate to slow pace. A timer with gold medal, silver medal and bronze medal "best times" could be helpful. Also, there *really* needs to be a fail state that isn't "soft lock". A level reset (or even a game over with the option to replay) is a must. Reloading the tab for one mistake sucks (although, as I mentioned above, it's hard to make a mistake if you're not going quickly).
This is a good start and I think a fun game could come out of this, it's just not there yet.