If you're going for accuracy here, you also have to consider color depth and resolution. The Atari 2600, under NTSC configuration, had a maximum resolution of 160x192 (some sprites using pixels a quarter of the width of "playfield" pixels, and the view likely stretched to match the TV screen), used 128 colors, and ran at 60 FPS. The NES precedes that with a resolution of 256x240, used 54 colors (
technically 64, 9 of which being duplicates and 1 that's not even visible so *shrug*), and also ran at 60 FPS. Subpixel movement is a no-no for both systems, so everything must be rounded. The sprites are also very limited, as a general consensus there should be no more than 3 colors (could debate on that because it's a little bit complicated), with only so many that could be seen on screen.
I could elaborate if you wish but I feel like I would just keep rambling on about how these systems work and start to fall away from the subject. Can't help it, I've always been a fan of some of the really cool stuff that old devs used to get around their system limitations.