Increase Your Brightness
Some levels have no difference at all. Even after you watch the ad and it gets circled, the area has nothing different between the images. Level 165 has this issue with the lady's ears.
As the title says you'll need to crank your brightness to blinding levels just to spot some of the color differences. I can't imagine a color blind person even being able to play this.
There's too many ads, and the game will detect taps wrong and remove time when another tap in the exact same spot detects the difference.
Other than those issues the game is mid. It would be better if I didn't have to drain my battery via brightness & ads.
Game also popped up an ad for a hint I didn't need. The "you're taking too long" thing popped up, then I clicked the correct area. I was forced to sit through an ad I never asked for.