A simple web game based on famous English mathematician John Conway's "The Angel Problem".
The Angel and the Devil play their game on an infinite chessboard, with one square for each ordered pair of integers (x, y). On his turn, the Devil may eat any square of the board whatsoever; this square is then no longer available to the Angel. The Angel is a “chess piece” that can move to any uneaten square (X, Y) that is at most 1000 king’s moves away from its present position (x, y)—in other words, for which |X − x| and |Y − y| are at most 1000. Angels have wings, so that it does not matter if any intervening squares have already been eaten.
The Devil wins if he can strand the Angel, that is, surround him by a moat of eaten squares of width at least 1000. The Angel wins just if he can continue to move forever.
What we have described is more precisely called an Angel of power 1000. The Angel Problem is this:
Determine whether an Angel of some power can defeat the Devil.
This is John Conway's description of The Angel Problem in Volume 29 of the MSRI's Games of No Chance. Conway originally proposed this problem in 1982, and offers cash rewards for those who could either prove that an angel of n power has a winning strategy, or that the devil can win irregardless of the angel's power.
We found the premise of Conway's problem extremely interesting, and realized that it would make for a very fun video game.