My first dedicated gaming system was the PS1, and in general I have no trouble going back to the sprites and chunky polygons of the mid-to-late 90s, whether on consoles or computers
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as long as I can upscale them to 1080P
Beyond that it gets a bit hit and miss- SNES and Mega Drive games look and sound fine to me and I've played plenty of 16 bit console games as an adult. On PC, I can enjoy 2D stuff like Sam & Max Hit the Road or the original X-Com but most early 3D, like the original System Shock, looks a bit too much like visual vomit.
Going to 8-bit, while the vast majority of NES games are too primitive to my eyes and ears, I have no problems with Game Boy/Game Boy Color games.
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(Well, at least the good ones, mostly made by Nintendo)
My limit is probably the very late 80s
I could pretty much enjoy games of any era except for games from the Atari consoles. Those were basically just shitty versions of contemporary arcade games. This was during the time when consoles were seen as portable arcades, which was still true well into the early 90s where a lot of Genesis games was just ports of arcade games. And as an aside, that would make Gameboy the portable version of the portable version of arcades, which was also true when it came out.
But going back to the Atari consoles, besides them just being inferior arcade games, I heavily dislike the aesthetics as well. It just looks like ass to me. Just look at this. That 7 at the top is so awkward looking. It's like ASCII art wasn't standardized yet or something, so all their art have this weird look where they're afraid of drawing diagonals or curves.
Their 7 is like this:
*************__________***__________***__________***__________***When ASCII art 7 is more like this:
*************__________**__________**__________**__________**__________**_____Check out that background colour in that tank game