difference game, eh?
okay, first thing i noticed is that you're using real pictures. often a mistake. hides the differences TOO well.
the pictures were edited quite well. i couldn't tell what was and wasn't part of the original picture at some points.
lack of hint button, compromised by being able to press tab and the differences would be highlighted. ye might want to try making a custom cursor for the game.
music is good. interface looks nice enough. but ye still have a ways to go... but, uh, try making different games. difference games are kinda boring.