Megaman Legends is "8-bit mysterious".
As you stray more and more toward narrative videogames, it becomes clear that games have real trouble competing with novels in telling a coherent, interesting story, often because you can short-circuit the whole thing just by getting a game over. And they have trouble conveying deep emotions as well as movies, because you can always ruin the mood by deciding to jump in place for 20 seconds. The strength of games is in conveying a sense of place. The best narrative games tend to drop you in a place and let things play out from there. Shadow Moses. Tallon IV. Hyrule. Even, and I want to emphasise that I do not speak from personal experience, Azeroth.
So what's the minimum you need to convey a sense of place? Often the best art is found where the constraints of technology are the tightest. The imagination is powerful, and if you can use that to populate your world, just the smallest hint of a thing will be enough to fully flesh it out. When I played the tiny Gameboy version of Zelda (Link's Awakening), my imagination was the one providing the dreary, leaf-swamped forests, the sun-drenched plains, and the cold, steely dungeons.
There are a lot of parallels between the bleary four shades of grey-green that Link's Awakening builds on and the shaky, barely textured polygons that Megaman Legends uses. On both the Gameboy and the Playstation, games appear to struggle just to paint pixels on the screen. It doesn't leave a lot of room for atmosphere-building--only the good games manage it. The secret, I think, is to stylise aggressively. Also, strict control of scope. So, two secrets: make the world stylised, keep the scope small, and make sure that detail is concentrated where the player is looking. Among the three secrets of atmospheric games are ...
Seriously, these are all one thing really. Find a fit between the hardware and the player's brain. Easier to do today, harder to do back then. Megaman Legends does it. The tradeoffs are draconian, and they weren't appreciated at the time, but I think they're the right ones for 3-D games on the Playstation. The biggest technique: reducing detail with draw distance, which is standard procedure now, but was rare at the time. Truth be told, the tradeoff is a little extreme. Small rooms are full of detail and actual clutter (a novelty for the Playstation). Big rooms are full of detail...in the immediate vicinity of the camera. About 10 meters away, a black fog makes the rest of the world invisible (note: sometimes it is a white fog). Face-to-face, the characters are the most detailed and animated on the Playstation. 10 meters away, they're a few big blocks stacked up.
Even though still screenshots make it look bad, it works better than you'd expect. The eye expects closer things to have more detail, even if the drop is extreme. The eye prefers to see real clutter instead of bare spaces, even if the clutter is 8-bit mysterious in its simplicity. ("Is that a key...or a clock?"). With most other Playstation games, you can tell that the game struggles just to put polygons on the screen. Megaman Legends, on the same hardware, has atmosphere.
So what does its atmosphere convey? Well, large parts of it are probably down to my imagination. Maybe you'll read its atmosphere differently. What I got was a sense of mystery at first. The world seemed designed for exploring; the beginning of Megaman Legends felt like the beginning of a Zelda game. But where a Zelda game spirals into a steady progression of tools and accomplishments, of dungeons completed and bosses defeated, Megaman Legends fosters a slow dread. Unlike Zelda, the dungeons aren't well-defined puzzle spaces--most are simple journeys to the bottom, then back again. Monstrous robots will try to kill you, because they guard some secret that no intruder must learn. Your weapons are puny and hard to aim. They are unreasonably powerful. You can see less than 10 meters. They lumber at you from the dark, audible long before they are visible. Killing them is hard, and often the only reward is money. No secrets: they die defending them, or the secrets never existed in the first place.
You quickly learn to fear any new noise in the dark. You can respond by ruthlessly grinding for money to upgrade weapons, or you can do what I did: get really twitchy and run away at every noise. Inch into rooms and jump back out if anything moves. Constantly dither between turning around and going deeper. Beat bosses by the skin of your teeth.
It's not clear whether this atmosphere happened by accident. I'm really tempted to say that it did, but I think I may be unfairly judging the Japanese game industry of the late 90s by the nearly-dead Japanese game industry of a decade later. You know what makes me decide that it was no accident? Another instance of genius--the control scheme. Seriously, the control scheme. Here we have another case of the game precisely fitting its limits--when Sony added two analogue sticks to the controller, Megaman Legends sprouted the same third person shooter controls that are used today. In 2000, the game had a control scheme that would be common by 2006.
So what happened after 2000? I titled this "Megaman Legends series" for a reason (though one reason is that I wanted to cheat and consider the best of both games at once). Capcom, after publishing the seeds of the modern third-person-shooter, abdicated to the West, which proceeded to incorporate all those seeds into the standard by 2006. Then in 2009 (or so), Inafuna, the creator, got a chance to make Megaman Legends 3.0. At least, I assume that this would have been a progressive, software-like refinement. It's possible that we would have gotten Megaman Legends: The Reboot. Of course this is all moot because Inafune left Capcom and Capcom canned the game. Inti Creates has made a number of Megaman spinoffs, but I don't think they will get the IP to Megaman Legends, so this really is the end.