So, loops of varying lengths, as described by Cliff B.
Fire the gun; watch the tracer; wait for the recoil; repeat.
A longer loop: After a certain number of bullets, you reload.
A longer loop: Picking up ammo every n people you kill.
A longer loop: Going to a "store" and upgrading.
A longer loop: Making it from one level to the next or one story point to the next.
A longer loop: Completing the game and waiting for the sequel. (I added this one myself.)
It's weird, my thoughts were headed in this direction already...I was thinking about writing an article on the minigame, the macro-game, and the meta-game, and defining these things, when I realized that games are sets of deeply nested challenges and \defining which level of challenge is macro and which level of challenge is meta really isn't that important.
Your most atomic challenge would be can you hit the badguy?
Your next level of challenge: can you kill the badguy? Hit him enough times?
Your next level of challenge: can you kill enough badguys to get the next powerup / stage / points?
Your next level: can you earn enough points to buy an upgrade or level up?
Your next level: can you finish the game?
Your next level: can you finish the game on a higher difficulty level, or 100% the game?
Your next level: can you beat your friends? Get on a leader board?
So, um, now that we've got "loops", how does that help us design games? Well, one thing Cliff said was that loops should be "tight." I know, intuitive. But there it is - I think you can tell if there's too much slack in your loops - (in hindsight, there was too much slack in the "earn points to get to the next mission" loop in *Spider-Man 2* - a little more dev time would have solved that - and, in *Spider-Man 1*, there was too much slack in some of your combat moves - punch, punch, punch knocks the badguy down and you can't hit him again until he stands up.) Another tool for our arsenal.
Cliff B points out that repetition is okay, if you're doing everything else right. I agree. I think games, like music, thrive on repetition. You recognize patterns and recognize variations in the patterns. This gives you a kind of pleasure. A problem with games these days, though, for me, is that there isn't enough variation. Killing that five hundredth not-a-zombie in Resident Evil 4 wasn't all that different from killing the first one. Compare with chess - each game puts you into a new situation you may or may not be able to handle. Hmm. Not a good comparison. Thinking out loud here. If firing your gun at a non-zombie in RE4 is the most atomic loop in the game, then the most atomic loop in chess would be moving a piece and waiting for your opponent to move a piece. Ok, let me amend. Each *position* in chess is a new situation you may or may not be able to handle. It may look deceptively like a pattern you know, but be different enough that the seemingly obvious move is completely wrong. Much like the non-zombie may turn out to be one of those non-zombies that sprouts the whiplash tentacle thing out of its neck. I wish I could make a melee combat system for a videogame that had the depth of chess.
But I probably can't. So I am willing to accept the repetition. In fact, if somebody tells me, "Your game sounds like it's too repetitive," I tell them, "It's repeated awesomeness!"
Boy my thinking is fuzzy this morning. I better stop writing before I say something really, really stupid.