Graphics are simple but rather pleasent. Gameplay is definitely to theme.
The little bits of story you worked into there were a nice touch, made the gameplay feel more meaningful. The difficulty level felt about right for me, despite having not playing that many puzzle games before. It felt like there was a good amount of variety between levels. You made good design decisions overall.
For improvements, a bit more work is needed on the sound design. The music gets a bit repetitive, and the digging sound isn't great to listen to. Remember, its worth 16.666667% of Ratings this Jam! A particle effect for the digging would also be cool, rather than just a black circle.
Overall, a neat puzzle game. Good job!