During crime scene investigations, eye witnesses can be really helpful in identifying who the perpetrator of a crime is. The problem is that people aren't always very oberservant and sometimes experience a phenomena called change blindness.

Are you observant? This game will help you to see just how observant you are!

In this game you will need to identify the part of the picture that changes. If it's too easy or hard change, the mask time (the time that the picture goes away before the changed one appears) or the alternation speed (how quickly the picture changes).