I am really conflicted about this game.
The crafting which takes place in-game, the absence of interfaces makes the games really immersive. I also like the ambiance and noises (and the sky !).
But it 's really difficult to play, I had to look into the wiki and the code to know to do things. It is really hard and long to dig stuff and it's quite discouraging.
The concept is really great but this game is not for everyone (if someone is new to minetest and/or just want a casual game maybe not =).
I think having more detailed in-game help would make the game more playable and avoid pausing to search instructions online or in the code; like detailed hints that you can ask when you're stuck and can't fullfill a challenge. It could be a mod if you don't want this in the core of the game. One could also add more or less detailed help with difficulty levels.