Its a bit frustrating to dig 3-4 squares in a round and find nothing, decide it was bad luck and play again, and then find nothing again.
My first impression when opening the game was "holy what, they made a whole game wtf". I was impressed by menus, the amount of text, button images in-line with text and settings.
As others said, it feels like the game is promising, but there really is no reward at all in the beginning, nothing to grab attention or keep you playing. If that got added, the game would be 10 times better.