Interesting. But the video title is a bit mis-leading. It modifies minetest, a "free, open source voxel game engine" [1], not Minecraft.

- [1] http://www.minetest.net/

Impressive. tl;dr it's possible to map a world made of squares into a torus in order to make it round. But I'm still really interested how the perspective was created of a spherical world although the mapping is toroidal.

I think he answers your question in this video: https://www.youtube.com/watch?v=joFWr3JzBOI

This is really cool!