Very right, I think not only this game but most of games are programmed to decide to do what with many conditional branch, like your saying. So we need to test everything to figure out the game results(routines). More important, we should usually do combo tests(tricks) to see if there exists game errors (or exam the rom codes to check bugs). Take a simple example for this game,
see this mpeg video. If you do nothing then the leaping enemy will always stay in jumping over and over infinitely. When you start to forward, the emeny will start to have different move because of your position 'event'. Try to see other movies on this site that will help you to feel it. Hope that can help you and welcome for any question. :)
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btw, Someone tell me that I can direct through the Jorker without fighting Firebug. Now I am messing up.