I enjoy the mining sounds haha.
It was a bit tedious at first but the upgrades made the game much easier quite fast. However I think there's still way too much clicking in the menu just to navigate, I think you could cut down on the UI a lot so players can get back to mining faster. For example I don't know why there's a sell menu when that's all the dug up items are good for, they should just be sold immediately when you dig them up. The item price is also fixed so I think it takes way too long a time if you keep getting fossils only worth 10 gold.
The visuals having mixed pixel ratio makes the game look a bit messy. I do like some of the pixel arts though. I also don't hear music, although there's a music volume slider in options.
Hope to see it developed further!