I imagine snake moving on its surface and then suddenly it gets fall into the empty area on the surface. And then its head
appears from opposite face. ;)
Actually I was thinking it would always stick to a wall, so when crawling across a corner into a "hole" it would just be entering a room inside the cube.
We will let STx start with 1x1x1 no "hole" cube with fruit on one of 6 sides to warm up ;-))