I imagine a small part here or there would need a bit of sacrificing but on the whole I see no reason at all why this game couldn't work on 3DS and if they decided to stop trying to make WiiU only games that would totally also work on 3DS and did it, I'd buy it. They won't though, need to try and twist arms to get anyone to buy their console anymore pretty much which is a shame.
I doubt I'd bother with other peoples stuff having to download it, but I'd like to do anything pre-loaded and make my own stuff a bit too, kind of like how F-Zero Climax on GBA works.