Very nice
Music was lovely, pictures where nice and the game was well made.
Definitely liked the fact that the player can control how the changes are made, adding or removing the differences at their own whim, makes it different to most spot the difference games.
(For people that have not spotted this, the difference will be changed on the picture your mouse cursor is on, for example if the difference is someone has a mustache on one picture and not the other, if you click on the mustache with the cursor it will be removed from both but if you click on the bare face with the cursor it will be added)