>>57740773Gen 3 had the usual complaints of muh water, also some criticism over dropped features from GSC like the day/night cycle and lack of compatibly with GSC (basically the OG dexcut, althout all the missing Pokemon did eventually became obtainable).
Gen 4 the biggest thing I remember was complaints about the Pokemon designs, the artstyle was shifting pretty hard at that point and it's when genwunners really started to get vocal. Gen 3 had some of that too but it was really a thing in Gen 4 because of the cross-gen evos. People called them digimons and that they were ruining Kanto Pokemon. Otherwise, I feel like Gen 4 was pretty well received overall, Platinum and HGSS were probably some of the most acclaimed Pokemon games at the time. A lot of the major criticisms people have of Gen 4 today didn't really become popular talking points until later, especially regarding HGSS. Or maybe I just wasn't aware of them back then.
Gen 5 had more genwunner seethe especially over Garbodor and the ice cream mons. Some people criticized the region for being linear and the story for being too in your face. So, same criticisms they get today mostly.
So there were criticisms back then of course, but overall it was a lot less severe than it has been during the Switch era. I was on /vp/ all the way back in Gen 5 and it was a lot less volatile than it is today. Most of the criticism back then was from genwunners slandering the new Pokemon and stuff like that, where today it seems to actually seems to be coming more from fans of the newer games looking back and retroactively picking the old games apart.
But, that's just my memory of things, and of course memory is flawed.