Minetest
Contributed by @Greelan
Link: https://www.minetest.net/
An open source voxel game engine. Play one of our many games, mod a game to your liking, make your own game, or play on a multiplayer server.
Note: There is currently a bug where the player may spawn in a block or the ocean and need to be teleported due to a bad spawn area. You can adjust the spawn point until the devs fix the issue.