4-player Battle mode is probably a lot of fun, but… they put guard rails on Rainbow Road. Which was indicative of a change in direction that shaped the series into something I didn’t enjoy as much anymore.
And all subsequent kart games (except maybe Super Circuit) took 64 as a template, instead of Super. The courses weren’t kart courses anymore. They started putting the karts on wider tracks with less demanding turns, making items more important and driving less important to win. Which is something I really don’t like, because I really like my racing games to require good driving technique above all else. I like F-Zero more than Extreme-G. I like Super Mario Kart more than any other kart racer I’ve played. Mario Kart 64 was when they turned the series into more of a party, and less of a racing game.