Honestly retro is anything I have the ability to backup and preserve. Now that digital stores are the default if I can back it up. It’s retro. Not much you can download and just have or not need an offline component.

It still feels weird to class the 360 era as retro, even though the launch is approaching 20 years ago. I’d say anything PS2/GC and earlier.

My opinion is that retro is at least 2 generations ago.

I’ve kinda decided that at this point anything that can natively output an analogue video signal is retro. Which would include Wii U I guess. But yeah, PS3 and 360 are kinda retro at this point even though it feels a bit weird.