Had a great time digging, collecting, and dropping off minerals. (Very nice drop off animations.)
Wish it took more minerals to win the game, so I just played it again! Plenty of potential here for more minerals, drill upgrades and more.
One small point of frustration was I am not small enough to fit into 1-wide holes when I dig down, and my drill cant dig a tile unless I'm directly above it, so downward digging was tedious. However sideways digging easily made up for this.
Laughed in the about/credits.