When my friends and I are in a tough combat, and I land a critical hit, it may not come with flashy images and booming sound effects...but if it makes my friends jump up and yell "w00t! way to go awesomeocalypse!", then that is a more or less instantenous reward, and to my mind, one that is considerably more of an ego boost. If I pull off a cool stunt, I may not have the satisfaction of seeing it beautifully rendered in 3d. But if the DM has one of the minions I'm fighting go "oh my god, didja see how that guy ran up the wall and flipped over the dragon? there's no way we're taking this guy, run away!" then that is a viscerally satisfying immediate reward.
I want to respond to your post, but I do find it interesting that when you talked about the "long term" rewards of pen-and-paper gaming, you talked about the social aspects, the world-building aspects, and the character-driven aspects. But when you wanted to talk about the "instantaneous Woot!" moments of an RPG, you talked about combat. Just an observation.
It's not necessarily the
type of reward that's different between computer and PnP RPGs--it's the manner, frequency, consistency, and might I add,
depth of the sense of reward that's different. If a player prefers constant, immediate, near-instantaneous reward feedback, a pen-and-paper RPG is the vastly inferior choice to a computer RPG, and that player is likely going to be frustrated when a pen-and-paper RPG isn't providing "enough" reward, and will likely try to push the game in directions that
will provide those levels of reward.
For example, in my recent Star Wars Saga game, my character talked a Grand Moff out of sending an entire squad of troops to a location where I knew the rest of my party would be. And as a player, I derived 1000 times more satisfaction from that moment than from any combat fight I've ever participated in, in
any RPG.
But the "reward feedback" for that moment took five or six sessions to create. The payoff for that moment took a lot more than my GM tossing a few minis on a battle mat and rolling for initiative. It took a GM willing to create interesting plot hooks, to integrate character actions into the flow of the story, it took setting up and managing an "acted role" on the fly, and then managing the consequences of the results of our interaction into the ensuing track of the campaign.
Once again, it's not about the ability of computer RPGs vs. PnP RPGs to produce the same types of "reward feedback." It's about the player's expectation of how quickly, how often, and in what degree the reward comes.