I can't say that this game is a good game, because I dislike liying, but though I think this is a bad game, I understand that you made it in two days.
I think, if you have the chance, you should remake it and improve its graphics. You should work more on controls because they are difficult to know, first time I played, I didn't know the controls and I had to refresh the page to see the tutorial. You should work more on menus and shark movement. Shark animations are cool, though as I said before, you should work more on them. This concept, with improved graphics, controls and menus, would be pretty funny.
I can say no more about this, I hope this is constructive enough.
Good luck, keep working.