There is a built-in cheat mode in this game that can be activated
by  typing in OUTLAW anywhere in the game. You can now use the [/] key
to  jump  to  the  next level and pressing the [I] will make your ship
immune against hits.
     If  you  press  the  keys  [1]-[7]/[F1]-[F7]  you  can choose the
weapons for player 1/2.