Nice Game!
I think that you have used the Limitation in a good way and I think the concept is really good. I also LOVE the music.
One thing I found a bit challenging was the controls because it was hard to keep track of where the cannon was and which way the ship was rotated and where the ship would move if I pressed W, I don't really have a suggestion how to fix this, but it could also be that I am just not the best player :D.
My High score was: 2060