Wow
This game was pretty incredible. Aside from the ingenious placements of differences, the art and scenery was powerful. Overall, it was very beautiful.
I did, after 30-ish minutes beat it. I'll confess I clicked madly once or twice. The only critique I can think (other than PLEASE make another) would be to add some music. Personally I had Kings of Convenience playing, seemed to fit nicely.
Fantastic job, Case. This was really so much more than I would have thought a "Spot The Difference" game could've been. Great work.