The Knife Rain game has attracted a large number of players with its simple and addictive gameplay. In this game, the main task of the player is to throw flying knives at the rotating wooden disc. At first, this task seemed very simple: whenever the player clicked on the screen or mouse, the flying knife would automatically fly towards the wooden disc. However, as the game progresses, players will encounter various obstacles, mainly other flying knives that have already been inserted into the wooden board. If the thrown flying knife hits these existing flying knives, the game will immediately end. Therefore, players need to avoid these flying knives and find gaps for throwing.

In Knife Rain, wooden discs are often filled with flying knives, leaving players with extremely limited space. The problem is that players must use all the flying knives indicated in the bottom left corner of the screen. This means that players may need to find space to insert the flying knife in very crowded situations. This is particularly difficult when the wooden disc rotates at different speeds and directions, and if there is only one suitable space left, the task becomes even more challenging.