About The Game

The game starts with a random pattern of green and blue grids on a 5-by-5 board. Each move in the game consists of clicking one of the grid position, which would toggle the colour of the current grid as well as each of its immediate neighbours (up, down, left or right, if they exists).

The objective of the game is to find a set of moves that reset all the grids to the colour blue. There are two different modes to play this game. You may wish to devise a strategy to solve the game in the quickest time, or you may wish to find the least number of moves to solve the game. Of course, if you can spot the optimal solution everytime, then presumably you can achieve both objectives at once! But you may be surprised by the subtlety of the game...

Not all starting patterns are solvable (how can you check if a particular pattern is solvable or not?). However, in order to spare you the frustrating and highly irritating wild goose chase, the current Java game version performs a background check to ensure that every game you play is indeed solvable. A time clock is provided for you to check your performance. When you have solved the game, the programme will compare how efficient your moves are with the optimal solution. When you are stuck, you may click the help button, which would display the optimal solution to the current pattern on display.

The Authors

This Java game version is written by Mr. C.W. Yeung at the Department of Mathematics, Hong Kong Baptist University. The check for solvability and the optimal solution are based on the results of a student modelling project by Cheng Wah Chiu, Cheng Yuk Wai, Ho Hau Kai, Woo Kam Chi, and Wong Kin Wa.