I liked the crayon esque artwork, really fits the little story you've got going on. The upbeat music also really added to the experience.
I feel like the fail rate might have been a little high. There were multiple instances for me of failing 3+ times in a row. Could maybe have done it like some other fishing minigames where you just wait until something catches. Could have the random "failed to catch" dialogue at random intervals.
Some minor nitpicks too -- the fishing line didn't animate with the bob of the ship, so it was disconnected from the fishing rod part of the time. The first menu button had the mouseover effect permanently applied which was a little offputting.
This is pure opinion, but I didn't care too much for the crayon effect on the text boxes specifically. Not the font choice or anything, or even the layout, just the use of the brush as opposed to a clean outline on the text boxes.