with the floorcasting engine, although maybe it would be hard to make the camera look up/down and handle horizontal portals going in vertical ones or vice-versa, I wonder if, even if the graphic quality is decreased a bit, such project could be taken on now that there are some more Nspire coders and some other people here interested in C? I think looking through portals would be out of the question, though, and the game screen size would probably not be full screen (more like Gemini or Star Fox 84+)

I wonder if such engine could actually be used? My concern is textures, though. I fear if the C compiler isn't too good, it may require assembly for the 3D engine and in both cases, I wonder if textures would be fast enough at such large resolution.

Yeah for the blurriness frame rate would need to be reduced in the first place