If you die during a warp malfunction, the game skips the tax-free
        shop and the next level.  You can use this to your advantage in the
        harder levels, especially in the Big Trouble stages.  So make sure
        you have plenty of lives left.  When you get to the level you want
        to skip, especially Big Trouble, just pray for a warp malfunction!
        If you get a warp malfunction, just kill yourself once (It's a good
        idea not to do this until there's only one alien left on the
        screen).

                                    (OTHER HINTS)

        1.  It is generally not a good idea to spend any credits until you
            have 500.  When you get 500 credits, buy the Super Weapon.

        2.  If you hold down the fire button (make sure to disable autofire
            if you have it on) from the moment you grab the Meteor Storm
            icon right up to the end of the Meteor Storm, you will get the
            secret $5000 bonus (This only works in version 2.4 and possibly
            the upcoming 2.5).

        3.  On Version 2.4, it is not a good idea to buy the $3000 weapon
            until you're in levels 51-75.

        4.  The weapons that cost $750 and higher are generally not very
            handy unless you have autofire (Ver 2.4).  If you do have
            autofire and have one of these weapons, what you have is an
            incredibly nasty weapon!

        5.  You can also "cheat" by using a hex editor and editing the main
            program.  Just find the part of the code that lists all the
            prices in the tax-free shop (make sure they are not part of the
            menu, if you modify the menu in any way the game won't run!)
            and change the numbers to whatever you want.  This way, you can
            make everything cost nothing if you want!  However, you'll
            still need $50 to enter the shop, and $400 for continues (or
            $200, in version 2.3).