Awesome game! That core gameplay loop of grinding, digging, and hoping to strike it rich with precious minerals is incredibly engaging. The art style is really cool, and the sound effects are good! Just out of curiosity: is the porcupine sound effect from Hollow Knight? It really reminded me of it! Also, I absolutely loved the playable credits, it instantly gave me Rayman Legends vibes. Here is a video of Rayman's credits:
It’s a small layer of polish, but it makes a huge difference in the overall experience. If I had some constructive feedback, it would be that spicing up the narrative and adding more variety to the environments, minerals, and enemies could easily take this game to the next level. Great job on this!
By the way, if you have some free time, I'd love for you to playtest my game as well and let me know what you think!