It goes on vibes. Historically I’d have said anything with an 8- or 16-bit CPU (NES/SNES, Megadrive, the surfeit of home computers before everyone standardised on beige-box Windows PCs). Nowadays I’d say anything slow enough to be emulated reasonably using present-day technology could be said to be retro, so PS2 would count. If video output is analogue PAL/NTSC, that probably also counts.
It goes on vibes. Historically I’d have said anything with an 8- or 16-bit CPU (NES/SNES, Megadrive, the surfeit of home computers before everyone standardised on beige-box Windows PCs). Nowadays I’d say anything slow enough to be emulated reasonably using present-day technology could be said to be retro, so PS2 would count. If video output is analogue PAL/NTSC, that probably also counts.