What in the...?
What the heck was that? Sounded like a big turd trying to get out, but it's stuck.
The theme feels very Pirate-ish, and you've created that effect of funny pirates without a doubt. In the effect-creating department, you get "Employee of the Month". But the music itself - ehh... It can do better. The emphesis was put more on the sound effects (the seagulls, the shooting, the pirate laugh) and less on the music itself. It's supposed to go the other way around.
If this was meant to be a solo piece for the piano, you'll need chords. If you want to elaborate it a little more, more instruments wouldn't be a bad twist after the beggining, such as an accordion or something like that. It can be better and remain Pirate-ish. If you establish the feeling from the beggining, it will stay out throughout the entire song.
Final conclusion, try to take this as an intro and create a song out of it. Good luck!
P.S. - This is not too shabby for a first submission.