Very interesting game this is.
I actually quite enjoyed playing this. I was some-what of a challenge in a few of those levels. I really loved your choice of music for this game. It was nice and calm and also calmed me down so I could line up the number better.
I also loved how the picture only appears after you finish the whole puzzle. The use of a timer was a excellent thing as well since you had to find the number first yet not knock into other numbers by mistake.
I really hope you make this into a series of some sort. I was very impressed by this game very much.
Full marks on both ends.