An excellent article on how the Shovel Knight devs balanced the look and feel of an NES game while trying to adhere to modern standards.
Oh man, this was a really interesting read.
I never owned an NES as a kid (I do now though!), and never played it enough to notice most of these quirks, but they were really interesting to learn about.
I always just assumed that Shovel Knight looked and felt like an NES game in style and gameplay, but it's amazing how much effort these devs put into keeping NES features that frankly, I doubt most people will understand or notice.