Really impressive work. He covers it at the end, but being able to create tunnels into terrain, walk through them and then make the terrain disappear. Or make holes in the ground and move them around to suck items in. Or dynamically erase or add to any terrain in real time. A lot of interesting gameplay opportunities here and surprisingly performant!
I really respect his work on the engine, the math, and the engineering is excellent, but I'm not sure it makes for an interesting game above and beyond what we already have.
Adding additional smoothness to existing voxel engines I'm not sure would have much effect, unless you have something specific like moving a ball on a smooth surface (but the SDF I'm seeing here wouldn't support that either).
As for "create a hole, then close it behind you", this is about as game-changing as open/closing doors (or tunnels with doors). I'm open to suggestion, but honestly this is amazing tech, I just don't think it will create very fun games.
Kind of feel the same about the demos I see of spherical or non-euclidean geometry games. Its very interesting, and impressive, but seems like it is an engine in search of a game.
Maybe one other thing to consider -- I think its usually best to have a killer game idea that seems fun, then design around it (and select the proper engine), rather than simply "I want to build an engine with some capabilities, then I'll figure out what games to make later."
Have seen this with a lot of software "frameworks" (web, game, graphics, etc.). Nothing wrong with writing an amazing tech demo just for the hell of it, but then when it comes time to do "real world" tasks, the frameworks are often in search of a fitting problem.
