MEGA MAN 64 / Capcom / Nintendo 64
Capcom saw Mario, Link, and etc. making successful transitions to 3D polygonal worlds and decided to horn in on that action with one of their flagship franchises. However, the year they did this in was 1998 with Mega Man Legends for the PlayStation. Mega Man 64 is a port of that game to the N64, an inexplicable full three years later when the 64-bit generation was coming to a close.
Still, it does fill a gaping Mega Man void left on the N64 when Capcom decided to make most of the 64-bit games exclusive to Sony. However, it didn't really fill it in the way that Mega Man fans wanted. There really isn't much remnant of the platformer action the series built itself on, instead it feels more like playing an old-school circle-strafey 1990s PC shooter. Just with a cute town hub to run through and delightful boutique shopping.
It also sorta reboots the whole Mega Man mythology and puts in in Waterworld. Mega Man starts the game in pursuit of some sort of magical crystal that has enough power to rebuild the flooded world or something. One airship crash later (we're all in airships instead of just ships for some reason), and Mega and crew wind up on some island that turns out to be key to the world-saving and the machinations of the evil robots and etc.
So it's more of a dungeon crawl than a platformer really, and one with a lot of long meandering segments in between the action watching kiddie animu hijinx unfold. It's also the usual crummy voice acting Capcom was infamous for in the late '90s; although a lot less of it here (and lower-fidelity) due to the 64 MB cartridge limitation.
Combat in general is chunky and shitty, and the design of the dungeon levels and big battles tends toward being terrible. There's a string of three boss battles early in the game that will really tell you all you need to know about it. The first two are fairly easy and simplistic, but the third gets a little too cute having you defend the city from an onslaught of bulldozer robots. You have to shoot down carriers that keep airdropping them in, but the Z-targeting flakes the hell out with flying enemies and the starting range sucks too much even if you buy the lone upgrade available at the shop. So you chase these things around in futility while the town is getting gangbanged by bulldozers. It's ridiculous, and the first clear sign you should just quit this game because it's never going to sort itself out.
Capcom clearly just wanted "Ocarina of Time, but Mega Man" and didn't have either a good plan or enough talent experienced with building 3D worlds to pull it off.
* Gameplay Video