I guess I'm the kind of guy who says that, yeah if the aliens come, then I suppose we've got try, but if they're really are that superior, I don't give much for our odds.
If you want to carry that rather silly argument to the absurdist conclusion... it's not like only get one chance to play it through and if you lose, the game deletes itself and sets your computer on fire. By definition, playing a vidja game not made by a masochist implies some level of fairness is built into the game whether or not you play by spirit of the game or 'power game'.
I try to always accepting a creator's vision, to let them tell me the story they want to tell. Sometimes I play everything completely straight. But I have no trouble admitting that other times I bend every rule that won't break. It just depends how I feel and how much challenge I want on that specific occasion. To me it's like choosing difficulty settings. Smetimes you want hard and sometimes you want easy.
Either way, I don't worry too much. It's a game, and regardless of how I want to play it, it'll still be there next time.