Test your mind.
The object of the game is to destroy or remove the object on the screen without running out of time.
To destroy an object you must draw on the screen an object that destroys it.
For example if a fish is on the screen draw a hook to remove it. If a boat is on the screen draw a wave.
If a gangster is on the screen draw a gun to shoot him.
Draw a bomb to destroy a building.
Some object can be destroyed by multiple different items.