Press the green flag to play! The instructions are in the game, but whatever :P Basically you just try to spot the difference between two images that have slight differences in each level, and once you do, you click on the part that's different on side 2 (The sides are labeled). The first level is easy but it starts getting harder and harder. Enjoy!
This was for an assigned project Btw I had one day to do this so that's why I used the Scratch sprites instead of drawing them heh XD