Elteria Adventures is a minecraft-sandbox clone with high poly characters and monsters. Explore massive floating islands, mine for resources and craft your hearts desires. At night skeletons appear and the passive creatures become hostile. The alpha Linux version is currently free and you can join huge online islands with your friends.
The current Alpha edition runs very well in Linux. I initially noticed the audio was pretty quiet and thought that it wasn't working, but turn it up and all the sound effects are there. Also, there is a bug where you use the teleportation device and end up in the same location... but if you quit the game and restart, you will transport to the new location. Other than that, it runs great and is pretty dang fun! I've played Minetest for years with my family and co-op is always funner because you can mine, craft and fight together.
Mint 20.1 64-bit
GeForce GTX 1060