A slot machine game that simulates a bank robbery is provided having a vault mechanical assembly that includes a plurality of doors and gates that may be sequentially opened by attaining winning outcomes at successive levels of the game. Upon completion of each level of the game, the game allows the player to either risk the player's winning and proceed to the next level or "cash out", thereby adding excitement to the game. In order to provide visual stimulation, the vault doors and gates are moveable between a closed and an open position during operation of the game. Simulated sounds such as explosions may also be used to enhance the enjoyment of the game and to attract attention to the game.