Collect the bottles on level 1 while holding down the fire button (otherwise you die). Do the same on level 2 while NOT holding down the fire button. Holding it down and moving into the enemies kills them, though. I don't know if the game was unfinished or what as trying to kill the octopus does nothing but end the game, and carrying on beyond brings the same result. I think it's bugged, as the option for music on/off makes no difference.
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