Some of it is practice, but it can’t be understated that many of those games were built with extreme low latency. Input low latency, CRT low latency.
The games were already “NES hard” add a couple frames of latency, and you may have halved the time to react to an in game event since you’re going from 1-2frames of lag to 4+. That really effects reaction time. And even for games like Super Mario Bros that are largely muscle memory since all the stages are largely deterministic, the added input lag just makes the game harder than you remember since you may already be used to the lower latency. Oh, and I haven’t even touched on jitter. You might be able to deal with exactly 3frames worse input and screen lag, but if there is ever any deviance from that, the game just got exponentially harder. You could expect almost no jitter on a NES (aside from slow downs from too many sprites), and brains are really bad at compensating for random jitter. I’ve seen demos of marquees played on monitors both with 8fps, one looked jerky, the other looked completely smooth, and the only difference was the smooth one had near zero variance in the framerate.
The games were already “NES hard” add a couple frames of latency, and you may have halved the time to react to an in game event since you’re going from 1-2frames of lag to 4+. That really effects reaction time. And even for games like Super Mario Bros that are largely muscle memory since all the stages are largely deterministic, the added input lag just makes the game harder than you remember since you may already be used to the lower latency. Oh, and I haven’t even touched on jitter. You might be able to deal with exactly 3frames worse input and screen lag, but if there is ever any deviance from that, the game just got exponentially harder. You could expect almost no jitter on a NES (aside from slow downs from too many sprites), and brains are really bad at compensating for random jitter. I’ve seen demos of marquees played on monitors both with 8fps, one looked jerky, the other looked completely smooth, and the only difference was the smooth one had near zero variance in the framerate.