The Impossible Letter is a challenging and enjoyable game where you must spot the one character that does not belong. The game starts with a 2x2 grid of letters, and your goal is to identify the different one and move on to the next stage. However, the difficulty level increases as you progress, and in level 50, you will be presented with a 10x10 grid of letter E, with only one F. The minute difference in the horizontal line at the bottom of the F might be challenging to spot, but it will test your visual recognition skills. Play for free on Greatmathgame.com and share your high score on social media. The game is controlled using a mouse. Have a great time playing The Impossible Letter!