I consider GameCube/PS2/XBOX to be undoubtedly retro. So anything Gen 6 and earlier. To me 16-bit era and earlier is just “more retro”. Gen 7 I think is arguably technically retro, but it just doesn’t feel retro to me.
I mean, 360 & PS3 games still feel like they’re just modern games with less detailed graphics, and the Wii feels kind of like part of the Wii U era to me; and that association with the Wii U makes it very much not feel retro. But any games released before Gen 7 feels unique compared to modern games, therefore giving that feeling of being retro.
When people are calling modern things they know are modern “retro”, I think it’s just a simpler form of saying “retro-style”. I mean, when I’m talking about modern retro styled things that aren’t videogames, I personally say “retro-styled” myself; and I consider that to be what people also mean when they call modern things “retro”.
For games, I have to disagree that Retro can also mean games that look old. Again, I consider these to be “retro-styled” as well, not “Retro”, which to me indicates its actual age. VVVVVV isn’t retro, it’s retro-styled. Alwa’s Awakening is an NES style metroidvania game released in 2017, designed to feel exactly like something that could run on real NES hardware. Then in 2022, they actually did just that; they ported the game to real NES hardware and released it as the “8-Bit Edition”. To play it, you either need to flash it on a cart and play it on a real NES, or simply emulate it on modern hardware. In my opinion, this game isn’t retro at all; it’s “retro-styled”, even if you consider the fact it released on an actual retro console.