It does look cool, but the voxels or cubes used in that video are too big and make it look a bit ugly and not too practical in this state.
All the above, of course, in my humble opinion.
Well, not sure if this is just for purpose of demo or that is what final voxel resolution is meant to be in game - thing with voxels is they need massive amounts of memory, so as time passes by, we'll see smaller and smaller resolution.
What I was excited the most was how different materials behave, it's the first time I've seen someone manages that with voxels. And honestly, I'd play game that has those physics applied to full world even if that's final resolution - I guess kinda like first 3D games that had very low poly counts, but they've offered something different than 2D games.