I agree with the conclusion this guy seems to be making.

That some of the games were made with square pixels in mind and look weird in 4:3, and vice versa for some other games. While the only one I disagree with among his specific examples, Balloon Fight, does not make my case stronger that most of the games look better in square pixels, there are so many games he didn’t list that do. Including The Legend of Zelda. It’s so wild that even though I grew up with them all in 4:3, in screenshots, magazines, manuals, and every TV in the neighborhood, it looks weird now. I know for sure I noted the squat tiles as a kid in those very first games (Duck Tales, Super Mario Bros.), but I got used to them and only now after a life on square tile games on other systems (like Game Boy) they are back to looking super weird.

Fred’s ImageMagick Scripts - unperspective - automatically removes pespective distortion in an image.

A basic explanation of the devcePixelRatio implementation in webkit