Berusky is a free logic game, published under GNU Public License and it's based
on an ancient puzzle named Sokoban.
An old idea of moving boxes in a maze has been expanded with new logic items
such as explosives, stones, special gates and so on. In addition, up to five
bugs can cooperate and be controlled by the player.
In order to leave each level (there's about 120 levels in the game) it is
necessary to own five keys and also to have a free way to the exit.