"Throughout the "Iwata Asks" interview there was mention of the core concept of "an NES game with the latest technology" and while I haven't played too many NES games myself, I wonder if this concept also contributed to the smaller scope of the game..."
NES games were not smaller scope. Metroid 1 is a massive game. So was Zelda1 and 2. Mario 3 is still one of the biggest platformer games ever.
Perhaps is it the perception of smaller scope that was the problem here.
I agree with you on Zelda and Mario 3 (without the whistles) but the first Metroid can be finished in 45 minutes.
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