Jack is faced with eight layers initially containing only two moving gaps, the gap moving leftwards travels upwards whilst the gap moving to the right travels downwards. Jack must jump through the gaps above him whilst avoiding falling through the gaps below. Jack can only move upwards by jumping through the gap above but he can also move left and right. Should he run off the edge of the screen he will wrap around to the other edge. Should he fall down a layer he will bang his head and remain unconscious for a period of time during which he cannot move. Every time he arrives at the bottom of the screen unconscious he loses a life.