The scenario: You, controller in hands, sitting on the sofa, staring at your television with a mixed expression of frustration and anger. You've hit a point in a game where you can't get any further, you don't want the strategy guide, you don't want to go pull up Gamefaqs. You just want to figure the wretched thing out so you can get on with the game you were enjoying up to this point.

The moment is as simultaneously recognizable and detestable as catching a fleeting glance of an ex at a party. The more you try to figure out how to advance, the less enthusiasm you have. It gets to a point where before you even pick up the controller to try again, you can feel it in your stomach -- a kind of grudge you don't even notice developing until it's in full effect. Before you know it, you don't pick up the game anymore at all.

This frustrating little phenomenon is the Difficulty Arc, a slippery slope where wonderful games can easily lose their footing and fall to their death, never to be played again. That perfect marriage of conflict and reasonable challenge rarely find their balance on the Arc. Only the best games manage to delicately hover there, poised as a hummingbird before a flower fat with pollen.

Hit the jump, where I dissect details and perhaps wave entrails at you. 

Let's begin with a little video (because somehow pictoral examples make everything seem a bit more realistic.)