Meh, it is OK. Yes, I would agree on power ups, but AI is not needed. MAYBE if you wanted to add AI, like when you get to increments of 1000 points, create a fisherman, who tries to catch you on his hook for another 100 points. His posistion would be based on yours, and so would his line and hook. Power ups would be nice, along with lives instead of just points.

Also, it looks as if your high scores page has been tampered with. 2147483647 points eh?