Some games are challenging. Others are grueling. Other still are a special blend of the two, pitting you against your own physical limitations but offering a clear reward when you successfully complete the puzzle. Such is the case with Challenge Your Eyes Free, a simple-to-play but tough-to-defeat game that forces you to find pinpoint differences between Chinese characters on 140 tiles.
The game is very simple in its layout. You start with access to only one puzzle. Every time you complete one, another unlocks. During each puzzle, you are shown a Chinese character. This character is hidden somewhere among 139 other characters that look very similar with only a minute different - usually one extra stroke. You have one minute to find the different-looking character and clear the puzzle. It's not easy to do because your eyes will actively cover for the difference, seeing essentially the same pattern over and over again throughout the puzzle. While the Chinese characters may be intimidating for some, they are a perfect way to format a puzzle game like this because they are clean and not subject to interpretation (unless you speak Chinese).
The game is free and has a small ad at the bottom of the screen. There are no upgrade options, and the menus consist only of "share" and "review" so there are no ways to decrease or increase difficulty. So it is very much a one-trick game, but that one trick is very enticing, especially if you like things that force you to think and focus more than just tapping the screen whenever a certain color ball appears. It may not be flashy or filled with special effects, but Challenge Your Eyes Free is challenging and just the right level of difficulty. Anyone who enjoys this type of game will have a blast.