This game is a great exercise for concentration.
The player has to drag numbers that are falling from the sky to each other correctly using mathematical operation enabled in the level to calculate the target value. Target value is displayed on the top of the screen inside the water bolt.
Every time the player calculates the target value correctly, he add some water in to the water bolt. The goal is to collect enough water to start the rain. When the rain starts, sea level rises and the stranded boat is saved.
If the player waits for too long, rain clouds will move away and the boat stays stranded. Player should calculate target values fast enough to start the rain.
Note: if more than one mathematical operation is allowed in the level (e.g. addition (+) and subtraction (-)), player can calculate the target value using any of them.