On the high score table, enter "ALF".  Now when you start to play
        the next game you will have infinite lives and near invincibility.
        
        If you manage to reach level 10, you're better off using your radar
        to kill the xybots.  Just line them up using radar and fire, you
        don't have to be able to see them.  Keep as many keys with you as
        possible because some levels don't have enough to complete them.

        There are short cuts to level seven on levels one and four - you
        get extra cash for using them.  If you have the extra energy upgrade
        try not to let your energy fall below 100m, because you lose the
        upgrade if it does.

        Drums are not just decorations - hide behind them when possible and
        use your zapper near to them to find more cannon power.

        On level eight, near to the top left hand transporter you can get to
        two white coins by blasting away one of the three walls around them.

        Don't split up in the two-player game, because it's easier to
        complete it together.

        The master xybot lives on level 11, and you'll need to stock up on
        double shot and extra shot speed to stand a chance of survival.

        Try to get one xybot to stand behind another - they'll blow each
        other apart.