That's pretty much it, that's the whole formula for making a video game. Okay, admittedly we can add "save the
From Super Mario to the Legend of Zelda and even wrapped within Halo 3, Red Dead Redemption, and Gears of War, and pretty much any video game you can there lies the simple formula. Given it's simplicity, the formula is easily maleable and can be formed to fit nearly any storyline. For instance get the bad guys and save the world can be adapted to get the bad Covenant and Librarian and save Cortana and the local universe for Halo 3 and get the Locusts and save (what's left of) humanity for Gears of War. Or in a quite litteral sense for Mario and Link, get the bad guys and save the princess. I'm not trying to completely diss the video game industry for lack of creative ideas or originality because clearly they know their target audience, someone like me who will play a good series forever even if bosses, temples, stories, and quests clearly get reused over and over again. There are plenty of people who would complain about that, understandably, but to those people I say "go play WoW then".
