Shin'en is an German indie developer(yes, that Germany that is homeland of Crytek) that does audio middleware, has done soundtracks for over 200 games and they develop games exclusively for Nintendo platforms and is listed as 2nd party developer.
"For instance, all of our shaders used in ‘Nano Assault Neo’ are not really optimized. We just used the first iteration of them because they were already fast enough. We looked later through the shaders dis-assembly and noticed we can make them 30-40% faster by better pipeline usage or better hints for the shader compiler.
As ‘Nano Assault Neo’ never had a problem running at 60fps (including a 2nd screen rendering at 60fps on the GamePad) we didn’t have to do that kind of optimizations back then. For CPU usage ‘Nano Assault Neo’ only used the main CPU core. The two other cores were almost idle, beside a few percent used for our audio thread.
(Launch eShop game; Nano Assault NEO on Wii U)
"It is already used in FAST Racing Neo. All features done." - Shin'en 2nd generation engine for Wii U is used in FAST Racing NEO also they confirmed that FAST Racing NEO uses 4k-8k textures "Since FRN we use 4-8k textures. Means hyper real graphics but 16x storage. Happy this is no prob on WiiU eShop :)" and that car in image below is in game model "Yes, the websites car is directly from the game." and not a promotional asset "Well, we are simply to small to build HQ assets just for promos :)"
(Please observe the reflections on the car)
Please do not confuse 4k-8k texture resolution with display resolution while Shin'en confirmation of 4k-8k textures hints possibility that FAST Racing NEO will be rendered at native FULL HD(1920x1080p) also Shin'en games are always at 60 frames per second.
FAST Racing NEO is a sequel to FAST Racing League for Wii which was released in 2011, FAST Racing League is inspired by Wipeout and F-Zero series also Wipeout was on Nintendo's platform as Wipeout 64 and released on November 3rd 1998 for Nintendo 64.
(FAST Racing League on Wii)
Several tweets from Shin'en related to Wii U;
I recommend you to listen this soundtrack from anime Redline; REDLINE OST - Yellow Line