A point I'll make is no one from that time thinks of it as "the 4th generation" it was the 16-bit generation, and that was the first time generations became a concept. They were specifically related to the Mega Drive and SNES as opposed to the SMS and NES. Because realistically, what was before? Atari 2600? Apple 2? Commodore 64? Vic 20? Arcade? It was a mish-mash of different things and there was no coherent generation of consoles until the 16-bit generation and the 8-bit generation only became a thing to really define how the 16-bit generation was unique; and generally people thought of everything before the 16-bit generation as 8-bit consoles.
But the 16-bit generation as a concept was a major part of the marketing push from Sega against Nintendo. Since the first third to half of the 16-Bit generation was Mega Drive vs. NES. SNES came in much later, and when it did it was too little too late, I think Mario World wasn't as well received as it could have been because the perception was that Super Mario 3 was the better game, that Mario World was a cosmetic update + Yoshi - and that didn't impress nearly as much as Sonic, the bigger and nicer looking sprites, the hipper sounding music, and the faster more varied level design. Not only that, but Streets of Rage SLAUGHTERED Final Fight. While SNES did have an initial boom of success, it eventually became the butt of jokes (I know, I was a massive fan of Nintendo).
The next major battle was Super Mario Kart (personally, I was enjoying the hell out of RPGs, the importer/RPG fanbase in Europe was really hardcore in the early 90s, one of the earliest things that happened in regards to videogames on the Internet was translation walkthroughs for games like Fire Emblem 4 and Dragon Quest 5. But, even though Mario Kart was big, it was also mocked pretty hard. I think this was the height of the battle of the system wars of the time. It was also when Nintendo was losing the hardest in the 16-bit generation.
Then, DKC was revealed, and it all changed.
DKC was Rare's messiah game for the SNES, it is literally the one that WON the war for Nintendo. It's importance in the 16-bit era cannot be understated.
- the impact of that game CANNOT be understated. It wasn't the last time either. For the last few years of the 16-bit era, Nintendo went from being the loser console to being the massively superior one.
It felt like a very long time, but in retrospect it was fairly short lived.
The most major blow to Nintendo was losing Square, but it wasn't even to Sega, it was to Sony.
Epilogue
N64 got overrun by PSX afterward, but Rare saved it from obscurity with games like Banjo Kazooie, Diddy Kong Racing, and (especially) Goldeneye 007. From 1994 until Ocarina of Time's 1998 release, Rare was perceived as being better than Nintendo. GE007 was, again, like a messiah for Nintendo. Only this time it did not win the generation for them. Nintendo lost to Sony in the 64/32 bit generation and again, the N64 felt like the loser console - but no Nintendo console EVER (not even the Wii U) was perceived as a loser console as much as the Gamecube (often nicknamed, "the Gaycube" at the time, which sounds silly today - but it was a console that everyone except kids was kind of embarrassed to own). Luckily, Wiimania really changed all of that for the better, and I think Wii U didn't suffer the same "loser" status as the Gamecube, despite being a poorer machine, was because the Wii kind of broke the perception that Nintendo was down and out, also the thriving handheld sector became much more apparent after the DS Lite came out.
Nintendo fans got ballsy with teasing Sony during the Wii era. It's the first time Nintendo had a console that felt like it was made for adults looking for something fresh. I wish I could convey just how huge Wiimania was, there was and has been nothing like it before or since in gaming history (think Donkey Kong, Mario 3, Ocarina of Time hype, and quadruple it, then double it, and then keep that going for about 3 years). People lined up in front of retailers every night, all through the winter, all through the Spring, and in the summer you could still catch people camping out in front, and it only got worse come August and the next holiday season... if that sounds nuts, it was nuts.
I describe myself as a little dose of toxic masculinity.