Hello. Here's my personal opinion after playing for couple of minutes.
I don't like the fact that I can see the exact position of crystals, it takes away from the dopamine hit of finding one randomly, this makes it little bit a chore. If I just dug around hoping for crystal then I'd like it more. The animations and stats presentation in between rounds should be snappier, it's needlessly slow. The game could use more juice overall - the animations and sounds of the projectiles and rock explosions to make it more satisfying experience. Hope that helps somehow. Wish you success in your endeavours.