Nvidia's Shield is a solid, high-end streaming micro-console with the distinction of using the same Tegra X1 silicon found in Nintendo Switch - which makes the existence of a high performance Wii emulator for the system absolutely fascinating. An official project, developed by Nvidia and Nintendo in partnership, is this an early preview at how Wii and GameCube titles could be added to the Switch library? Our first look at the emulator running Super Mario Galaxy proved compelling, but follow-up analysis on The Legend of Zelda: Twilight Princess tosses us a curve ball, in that it's unlike any other version of the game available on the market today. It's still emulation - but with very specific customisations that set this release apart from the pack.
As things stand, we only wish that more Wii-emulated titles were available for testing - and that they were easier to come by. Right now, just four games are supported - Zelda, Mario Galaxy, Punchout and New Super Mario Bros Wii - and they're only available for Shield owners in China. Nvidia and Nintendo have done a pretty thorough job in locking out the games for other Shield users: you can only access them on Chinese hardware, and without access to specific Chinese social media platforms, they're impossible to buy even if you could access the appropriate store on Western Shield hardware.
Having overcome the availability issue by importing a Chinese console, we're now getting a sense of how much thought and effort has gone into this Nvidia/Nintendo collaboration. Super Mario Galaxy had full, localised Chinese text, perhaps suggesting that the developers are doing more than simply wrapping an emulator around the existing binary. Zelda: Twilight Princess goes much further - yes, there's the same localisation effort (obviously on a much larger scale for an RPG) but the game itself is a curious amalgamation of both Wii and GameCube versions, with one or two bespoke flourishes.
If you recall, the Wii version of Twilight Princess was effectively identical to the GameCube version, albeit with 16:9 support and waggle controller support. But the key difference was in terms of its presentation, with the Wii release mirroring the entire world, inverting the position of everything on-screen. It meant Wolf-Link howls from the right side of the Zelda logo, while the other versions have him appear on the left. More importantly, it also makes Link right-handed on the Wii version - mapping the way most players would hold the Wii remote on the right, swinging the sword using motion controls. The Shield release undoes all of this, possibly because the move to a standard controller negates the need to flip the presentation in the first place. The whole world reverts back to the GameCube style, which defies the idea that it's simply emulating a basic, untouched Wii release.
It's fair to say that the Shield version is a bit more involved then. One theory is that it could be the GameCube version at its core, tweaked to add in a widescreen view not available originally. Only the Wii version had a 16:9 aspect ratio at the time, but starting with a GameCube build would keep the world in its original state, and involve no workarounds for adapting motion controls. Then again, the HUD is completely reworked - repositioned with new button icons to match the controller. Shield receives a unique version of the game, combining GameCube's left-right perspective, the Wii version's 16:9 widescreen mode, while also getting a resolution bump similar to the Wii U HD remaster.
It's an amalgam of versions then, but a look at the rendering specs does suggest that we are still looking at Wii emulation as the foundation point. Just like Super Mario Galaxy, the internal rendering resolution is 1920x1404, a 3x boost over the original on both the X and Y axis, with some mild super-sampling on the vertical when viewed on a 1080p display. This heightened pixel count is paired with a significant boost in texture filtering quality, just as we saw previously in Mario Galaxy. Up against the Wii U remaster, the Shield's Zelda emulation does fall short though - obviously the higher HD quality textures are not present, and on top of that, just like the original GameCube and Wii releases, there is limited anti-aliasing.
The Shield emulation is obviously more rooted in the initial 2006 release and unlike Super Mario Galaxy, there isn't quite the same timelessness to the presentation - without the fineries of the HD edition upgrades, Twilight Princess shows its age, especially when rendered at higher resolutions. Its one saving grace is that every scene does at least run in-engine. It helps that Nintendo renders everything in real-time 3D, meaning that everything is scalable to higher resolutions. This isn't quite the case for Mario Galaxy's opening stages in its Shield incarnation, which uses the compressed pre-rendered cut-scenes of the Wii version, forever stuck at 480p, and looking rather ropey as a result.
Performance-wise, Twilight Princess on Shield is the only Nintendo title that targets 30fps rather than 60fps - and this presents a potential problem for an Android-based platform. Every 30fps Android game we've seen has featured obvious judder from improper frame-pacing, with new frames delivered at 16ms and 50ms intervals in addition to the proper 33ms. The good news is that the Nintendo emulator solves the issue completely with a flat 33ms line from start to finish, punctuated only by a very occasional, single dropped frame. It's a solid showing in line with the original releases of Twilight Princess on GameCube and Wii, with a consistency that persists throughout the first few hours of play we ran through our performance tools. In short, the emulator's 9x boost to overall resolution doesn't come at the expense of smooth, consistent performance.
So, what's the takeaway here? First of all, we can't really draw too many conclusions on a prospective Twilight Princess release for Switch, even though considerable effort has clearly been expended on getting a key game well running on the Tegra X1 chipset. For our money, if Nintendo were to bring this title to its console hybrid, Wii or GameCube emulation wouldn't deliver the best experience for users. With access to Tantalus' work on the Wii U HD Remaster, Nintendo already has a superior, more appropriate version of the game better suited for a Switch release - and its track record in delivering great Wii U ports is second to none.
But it's the approach and methodology seen here in bringing an emulated Zelda to the Shield that is more telling. In reversing the perspective back to the GameCube original presentation, reworking the HUD, tailoring controls for the Nvidia controller and delivering full localisation, Nintendo and Nvidia have gone beyond the call of duty here for what is a relatively small-scale, single territory release of a 12-year-old game. The Tegra X1 emulation core for supporting Wii titles is solid, but clearly, the platform holder isn't afraid to make changes to the original game for an improved experience. This isn't shovelware in any sense - the emulator is highly optimised but Nintendo is pushing even further here, not content on just repackaging untouched code.
So is this approach a preview of the emulation experience that is heading to Switch at some point? We must remember that Shield does run Tegra X1 with higher CPU and GPU clocks than Switch, though its Android overhead is onerous - a disadvantage the console hybrid side-steps gracefully thanks to Nvidia's NVM graphics API. But the fact that the emulator exists at all - and that it is so performant - clearly demonstrates that a lot of engineering has gone into this project, far more than a limited Chinese release of just four Wii titles would warrant. The resolution bump is prodigious, but it's the idea of Nintendo tweaking the experience via game code updates that is so intriguing. As a proof of concept, Shield's Wii emulator is really impressive - and hopefully the immense promise seen here will eventually benefit Switch too.