4 Differences is a spot-the-difference game on Kongregate. A sequel to 5 Differences and 6 Differences by Ivory (AKA Ivoryboy) where you have to find four differences between two pictures, while listening to the soothing music by Hugh & Saturation.
There are 13 levels in the game and on each level, you are given two pictures that are almost identical, but has four differences. The pictures are dynamic images where objects move on a loop and the moving objects may contain some of the differences. In order to increase the difficulty, one of the images is mirror-imaged on some of the levels. The graphics are quite detailed and the images look almost photo-realistic. Some levels scroll, some move with the mouse pointer, while some develop themselves as the player finds differences, revealing more differences. Spotting the difference can be quite difficult on some levels, but there is no scoring system, so there is nothing stopping you from clicking on every part of the image until you find the difference.
- There is an Xbox 360 reference on a building in one of the levels.
- The name "Hugh & Saturation" is a play on "Hue & Saturation", two important aspects of an image.