Alter photos - 1st Set (25 pics)

The project consists in modifying a provided set of 25 photos and create 3 versions of each original photo containing 5 small differences. The altered images will be used in a “guess the differences” mobile game in which the user must identify the differences (like this game: [login to view URL]!-free/id880583496). The requirements are: - for each original image (500 x 500px), you will have to create 3 versions, each version containing 5 subtle, but visible modifications. There will be 3 x 5 = 15 modifications for each original image. - each version must have the same size as the original photo (500 x 500px) - the modifications must be unique between the 3 versions - the modifications must be scattered all around the photo - the modifications must be of multiple types: elements added, removed, modified (form, color, size), mirrored etc - each difference must have a size between 40x40px and 120x120px - only as an exception for certain pics - you can make changes to an area between 25x25px and 150x150px. This is only if you have no other options / ideas. Please do not go beyond these limits and try to make the small modifications as visible and the big modifications as subtle as possible! - each new difference must integrate well with the image (it must make sense) - the hardest part it will be to find ideas for the differences (must not be too obvious, but not too hard either)