I dig it! I really felt like I was a cool rat with scurvy.
The controls are tough - but that's okay! That's the idea and concept of the game!
I think a gentler tutorial section would have been good - wider passages to sail through.
One thing I think would really help: the heart system works very well for fighting the other ships, but it doesn't work great for colliding with the barriers! If you turn too deep and run into the wall, you're almost guaranteed to die because your hearts tick down so quickly. A solution I think might work - maybe when you hit the wall the ship bounces back towards the center? That way you have more room to correct your steer.
Cool concept, and well executed! Well done!