The basic gameplay requires you to find five differences between two pictures. Just touch where the difference is and Line Hidden Catch will mark it on the screen. With a 60 second time limit, you have to quickly scan the pictures and find the differences.
Along with the Line avatars, you can also unlock and download photographs from real life. These images are more difficult to find the differences because of the amount of detail in each one. The images packs contain five images to compare and if time runs out, the game is over.
Each game requires "one heart" which refills every ten minutes. The social aspect of Line Hidden Catch is that you can send hearts to your Line contacts so they can continue to play. Line Hidden Catch will also add your friends so you can challenge each other with your high scores. You can also use powerups in the game like photo hints, the "Magic Pencil" that will locate a difference for you, and a time extender.
The good thing about Line Hidden Catch is that the pictures will randomize difference each playthrough, so that each round will be different. Line Hidden Catch is a fun game, but needs Line contacts to make the game more challenging by playing against friends.
Line Hidden Catch is a fun game, but can get frustrating with the real life locations.