BESIEGE

[by João Neto] Start with the NxN board full of stones. Then, alternating moves,
each player removes a stone (that stone is not captured) When a player makes a
square, he captures all the stones inside that square (no diagonal squares).

E.g.

x x x x x 5
x . x x . 4
x x x x x 3
x x . . x 2
x . x x x 1
a b c d e

If a player removes stone e1, he will capture stones c3 and d3

When there are no capturable stones left on the board, wins the player
with more captured stones.