Some other feedback: I saw RGB split visual effect in this game. It looks cool, but it's not eye friendly. I suggest add a toggle to disable it.
Balancing: Increasing depth increases resource gain by 3x but block hp by 5x, which means I can only get 0.6x resources overall. I feel it's only useful when I run out of blocks to dig in lower depth, and when that happens, it's more penalizing than rewarding.
I suggest change it to the other way around: Make resource gain mult grow faster than hp mult, like 8x vs 5x. This way it's rewarding for the player to unlock new depths.