I could care less about games looking like they're "authentic" WRT to curvature or phosphor grid pattern, but things like aspect-ratio correction (non-square pixels), colour switching[0], or cheap transparency tricks through composite[1] are another matter entirely.

[0]: http://www.aaronbell.com/secret-colours-of-the-commodore-64/

[1]: http://nerdlypleasures.blogspot.fr/2015/03/the-case-for-comp...