Hi Donna and welcome to the challenges!!! I like your puzzle game and I think it's very cool.
You asked for it ;).
->The puzzle pieces seem to have a slightly pixelated edge, I used Illustrator to clipping mask the pieces on mine, Illustrator is a better program than Photoshop when working with shapes and paths.
->The image layer (where you drop the pieces) seems to be off center by 2px at the bottom and by 1px on the left. If you hold Alt and then use your arrow keys you can drag objects 1px at the time.
->I would have used "Return item to start point if dropped outside->a correct target" and "Allow only one item in each drop target" on the Drag & Drop settings
->Once the puzzle is completed you could add the picture of the bunny to fade in on top of the puzzle pieces and then fade in a restart button
->Also adding a bit of sound effects is always great feedback for the user, have a look at
www.freesound.org Hope that helps and see you next week.
PS. I like you avatar pic