KShisen has several possibilities to change its behavior. All options can be changed from the menu Settings.
The options will be saved automatically.
In the sub-menu Size you can change the number of tiles on the board. The more tiles you have, the harder (and longer) the game will be.
The sub-menu Speed sets the time for the tiles to disappear when connected correctly.
Choose your game skill in the sub-menu Level.
Checking this item makes the game even harder: If a tile is removed, all tiles lying above it will fall down one step.
If this menu-item is checked, only solvable games will be created when a new game is started. Note: You may still choose the wrong way and have to try again if you didn't solve the game, but if it's checked, the game will be solvable.