One of Hasselblad's cameras has a Double-Full-Frame sensor.
Does that mean that the lenses needed for it are incredibly complex to build (to have a sharp, high quality, abberation free image on the borders)?
Back before digital cameras, studio enthusiasts were used to 6x6 (6cmx6cm) (or even 6x8) camera which have about 4 times the surface area of 35mm film (24mmx36mm).
If you look (for example) at the Zeiss lens for such cameras (as example for Hasselblad body) you can see that the same optical formulae are also used for 24x36 lenses (Zeiss optical formula is indicated by the name Planar, Distagon, Tessar,...)
Theses lenses are bigger and usually built for high-end users but designs are not very different.
It's actually easier to make sharp lenses for a larger format. A good example of this is the Gigapixel project that used a large format film back from a spy satellite to produce images on film that can be scanned at a resolution of one billion pixels.
The frame was 18" x 9" with a diagonal 19 times larger than a standard APS-C frame. The custom made 215mm f/22 lens is equivalent to a 11mm f/1.2 lens on the smaller format. Whilst this lens could probably be made, at a price, it wouldn't be able to resolve anything like 1 billion pixels.
Lenses for larger formats actually tend to be simpler designs. They are still precision made, and expensive to.produce but tend to have fewer elements than the ultracorrected super complex designs found in the 35mm format domain.
Lenses for 35mm SLR cameras obligates to maintain a fixed distance from lens mount to sensor that is dependant on the body depth (about 47mm for Nikon and very similar for Canon bodies). Additionally, in the case of short focal length lens, the rear principal plane cannot be placed on the proper distance that is short than the camera body is. Do not forget that the camera body contains the reflex mirror and it needs some room to be operative. This is the main difference between SLR lens design and its counterparts of the same focal length but designed for range finder cameras with no mirror into the body.
Cameras for bigger formats as the former 6x6cm film cameras or the current digital SLR provided with digital backs like Hasselblad, Mamiya or PhaseOne, share the same problem because of the presence into the body of the mirror mechanism. The only group of cameras that do not compromise the lens design are the view cameras, both equipped with film or digital backs. The view camera is empty and of flexible length. The lens design can be sometimes surprisingly simple and located at the proper distance, no matter if it is a wide angle or a telephoto lens.