While Nintendo and Sega have given us a handful of "3D classics" for the Nintendo 3DS, a new emulator promises to open up the field considerably. 3DNes is a Unity-based emulator that, as the name suggests, converts NES games into 3D.
Unlike SNES games, which have four background layers, NES games have a single layer for the entire background, making automatic 3D conversion tricky. According to the developer, 3DNes is based on an algorithm that analyses and separates flat backgrounds into singular, 3D objects. It's not just simply stretching out pixels on another axis, either: round objects are rendered as spherical or tubular shapes.
Super Mario Bros. is by far the most successfully emulated title here -- even if the early beta footage has the plumber stuck running backwards for part of a level. Other games with fairly simple 3D backgrounds, like Mega Man, are also pretty effective, while highly complex games like Contra and Castlevania struggle. There's been some discussion as to whether the developer, Geod Studio, is tailoring the algorithm on a game-by-game basis, but he claims that the algorithm has been written for and tested extensively with Super Mario Bros., which is why there's a gap in quality between it and other titles.
Geod Studio hopes to improve the number of games that work well through subsequent beta releases. "If the emulator can render decently [even one tenth of] NES game collection," it's already a big success for me," Geod's Trần Vũ Trúc told users on the TASVideos message board. He also suggests that there might be the potential for users to individually tailor the emulator for certain games, but he wants to ensure there's "a strong emulation engine as the backbone" first.
Right now 3DNes is in a pretty sorry state. It's available online in a WebGL Unity player, which is extremely unstable and only works in Firefox. We managed to get a test ROM to load only after switching to an AMD graphics card, but nothing else worked. Trần acknowledges that the web Unity player isn't great, and says subsequent betas will be available in an executable format. For now, you're probably better of wistfully watching all the videos Geod has uploaded to YouTube, and patiently waiting.