Very cool use of both platformer and puzzle mechanics, and nice level design too!
I love the minimalist but cute graphics, the mole is adorable and fits very well with the environment elements too!
Nice audio choice too, I believe its very important to use smoothing relaxing audios while making puzzle games, since it helps the player fell calm while playing again difficult levels.
The only advice I would give is to add some extra difficulty, maybe letting the iron blocks fall fown when directly diggin beneath them.
Congratulations on such an entertaining game!