It's an interesting take to turn digging into a countdown mechanic, and the pickaxe does give some strategy in not having to push down blocks. Pretty similar to Mr. Driller.
I kinda wish that the player can see more far down though, especially since the game seems to really emphasize planning out how best to push and break blocks in a way that benefits the player. Otherwise, I often find myself stuck wasting time for the pickaxe or for the right column to be pushed down.