It's not just "that". Minetest is actually a "voxel game engine", and allows all sorts of things. A better showcase is the community's mod catalog, "ContentDB" [1].

Some mods/games even try to break out from the cubic theme, for instance "Little Lady" [2] or the "Rocks" mod [3]

It should be mentioned, though, that beyond those "extreme" cases, the MC-like voxel model is vastly easier to deal with for mod creators, and that's really a key point. That's the kind of thing a high-school kids can hack because it's Lua and PNG textures all the way.

[1] https://content.minetest.net/ [2] https://content.minetest.net/packages/Just_Visiting/littlela... [3] https://content.minetest.net/packages/Just_Visiting/rocks/

If I recall properly, Minetest started out as an open-source Minecraft clone hence the aesthetics.

Best looking modern voxel games I know of are Teardown[0] and Shadows of Doubt[1].

[0]: https://store.steampowered.com/app/1167630/Teardown/

[1]: https://store.steampowered.com/app/986130/Shadows_of_Doubt/

Check out Voxatron (https://www.lexaloffle.com/voxatron.php), it's like Pico8, but in voxels.

Smooth of voxel terrain isn't new, ultimately it doesn't play well so it isn't included in most voxel games. Minecraft stores data as voxels but renders as polygons (blocks). There are voxel rendering techniques as well. But at the end of the day it comes down to triangles or rays, right? So that voxel data has to be turned into polygons sooner or later, and the more magic you do to it, the less coherent these polygons are as a gaming mechanic. Blocks turn out to be fast/cheap to render and are highly usable in gaming mechanics.

I think the reality is that in Minecraft for example, every voxel is in memory, including the 99% of them you can't see. In minecraft, a chunk is up to 16x255x16 or 65,536 voxels, and with a view distance of 10, that's 21x21 or 441 chunks loaded, with up to 28,901,376 voxels in memory.

So whatever we do to turn voxels into polygons, we're going to likely be doing it across an enormous amount of data (relative to a home computer).

(And remember, in minecraft, chunk generation occurs live too. No world pre-gen. As you walk around, the game is inventing the world 65k blocks at a time!)

The undeservedly little-known Planet Explorers¹ has a rather nice voxel engine and is using it well. Mine anything, dig tunnels in any shape, modify terrain, etc.

Without the cuboid look.

¹ https://store.steampowered.com/app/237870/Planet_Explorers/

Outcast was also great

Also first thing that came to my mind. Also, I can recommend playing the remaster (Second Contact).

Back then they had a bug in the naming of the quality settings, so that the high quality was labeled low and vice versa.

Played the whole game in bad quality until near the end

There was also Comanche: Maximum Overkill, one of the first voxel-based games, quite impressive for 1992!

https://en.wikipedia.org/wiki/Comanche:_Maximum_Overkill