This app is based on the classic "Spot the Difference" game which involves two seemingly alike images that's juxtaposed - except nothing is as it seems from the get go -

As you look closer at every section and truly survey every detail in the app, you will find significant differences - such as a random slingshot hanging from the branch on the second image where there's none in the first, or the bulbous face of a mutant outside the cottage window of image one - where there's only a midnight scene in image two.

This game features 150 levels and limitless time! Each level should provide you with a total of two hints.