The screen is broken up into 14 x 13 tiles or checks. When the player passes over the tiles, they disappear so each tile can only be walked over once per level. Some tiles are taken up by skull and crossbones which kill the player if walked into. The skulls turn to time bombs one at a time and the player must walk over them to defuse them before they explode. They must avoid the skulls and make sure they do not block off a possible future route by circling it. Some tiles are also flags which can be collected for bonus points. When all skulls have turned to bombs and been defused, the level is complete and begins again at a harder level. As the game develops, stomping boots are introduced that move around the playing area. These are also deadly to the player. Less