It is
also a basic vanilla Minecraft clone (the wording is kind of poor). If you install it you can play a basic game.
It's also in the repos of every linux distro I've tried it on (Fedora, Ubuntu, Debian), and if it isn't it builds really easily (even built on my Chromebook with both crouton and crostini).
You can also add "mods" to it that add a ton of rich features to the game. I recommend adding one at a time tho as they can make your server unstable (mods vary in quality). The minetest core is rock solid stable IME, but not all mods are.
If there's any interest, I can write a blog post about this with getting started instructions at playing and configuring. I'm not affiliated with the project, but I'm a big fan and use it at home with my kids (and a server I setup on our LAN).