GoKawiilMotion is only one part of why retro games don't look right on modern TVs; resolution is the second major factor. CRT displays don't have "native" resolutions like their LCD and OLED counterparts. They can render many different resolutions without the smearing that happens when you try run a flat-panel screen at a resolution lower than its native one. The console gaming industry standardized around two resolutions prior to the PlayStation 3 and Xbox 360 era: 240p and 480i.
Today, 240p and 480i are defined as "standard definition" resolutions to differentiate them from the "high definition" and "ultra-high definition" resolutions that came after. The majority of CRT TVs ever produced were standard definition sets. Some high definitions sets were made, but by the start of the HD era, LCD screens had begun to overtake CRTs in popularity.
Yet another nice example of a developer keeping a midrange, composite-only, consumer CRT nearby to check how the game's visuals would look for the end user. (image via @crtbot.bsky.social) — CRT Pixels (@crtpixels.bsky.social) 2025-06-27T22:36:07.415Z
The number in each resolution is straightforward: 240p involved a CRT TV drawing 240 horizontal lines, while 480i saw it draw 480 lines. The letter that follows each resolution is more complicated. The "i" in 480i is short for "interlaced." When displaying an interlaced signal, a display completes two alternating passes to draw an image. It will first draw all the odd-numbered lines before doing the same for all the even-numbered lines. This sounds like a convoluted way to render an image, but at a time when technology was limited, interlacing allowed broadcasters to save on bandwidth. One byproduct of interlacing was producing the flicker CRTs are known for.
By contrast, the "p" in 240p stands for "progressive," which it works exactly like it sounds. Such displays will draw all the lines in an image consecutively. All HD resolutions are progressive resolutions. 240p allowed CRT TVs to render an image without flicker, and before the PlayStation 2 and GameCube era, it was the resolution most consoles targeted for that reason. However, standard definition CRTs render 240p differently than modern TVs. They leave the even-numbered lines black. Many people refer to these lines as "scanlines," though that's technically incorrect. Still, those lines, especially when paired with pixel graphics, are what most people think of as the CRT look.