I like the art, clean vector graphics. Cool bubble particle effects, wave effects. The birds were a nice touch, except there's a couple flying in place where you spawn in.
For some reason when the hook enters the water the framerate drops drastically.
Since you can't control the hook horizontally you can get stuck without any fish to catch. I also didn't understand the bait system -- I had assumed it was based on the colors, but I kept getting fish when I was using a different color bait. Sometimes it would also take a really long time for a fish to catch the hook.