There's an interesting point there about how the games on the old consoles are practically un-playable today, but I think it has less to do with graphics and more to do with other aspects of gaming that have changed.
I tried Game-tap for a while as well as downloads from Wii's virtual console and XBLA, and I always found that the experiences could not satiate me the same way that watching old movies or reading old literature can.
I think once the PSOne and the N64 took over as the mainstream consoles the nostalgia that we feel for our old games became twisted with the 3D modeled games that we've gotten used to. And even more important than the added dimension, since we're still seeing new 2D games of all genres coming out to some success, is the paradigm shift of overall design of games, which is, in my opinion, due largely to the complete assimilation of saving.
In a game today you die, you start 5, 10, maybe 30 minutes back from where you were when you died. Enjoying a game today means enjoying the game play and equally enjoying how the experience changes as you progress. Starting from scratch would be almost unheard of to younger gamers, and I think even most older games have gotten so used to it that going back to our "roots" is more frustration than anything else.
The addition of saving also means that the challenges of the games we grew up with are not the challenges of games we play today. If killing our avatar is nothing but a minor obstacle then other methods to hang up the player are necessary to create a sense of challenge. The kind of games we have now have so many other streams of input coming to us while we play that we're forced to use skills beyond our twitches to beat today's games.
Getting through an NES game meant becoming an absolute master at the particular game's mechanics--learning the controls, timing the events, understanding every cue and pressing the correct button at the correct time, every time. Yesterday's games were completely unforgiving, die here--start over. We're no longer equipped to handle games like that because we're not practiced in those kinds of games anymore.
Graphics are certainly a large part of what makes a game appear old but the game play is what makes it feel old... and the fact that they're putting Ataris into museums is what makes me feel old.
