MineClone 2 is one of the best Minetest engine games I know.
It implements the mechanics from Minecraft as accurately as possible. It's fun to play with friends as well as in Minecraft. But the coolest thing is that MineClone 2 can be easily customized to suit your needs (if you have the right skill, of course). In general, this is a plus of the engine itself, but without games like MineClone 2, it wouldn't be so cool. The game still needs bug fixes, but in general it is already possible (and necessary) to play. I wish the developers good luck in the further development of the project!