This felt like playing dungeon crawler Bomberman (in a good way). Safe to say, I liked the game's mechanic, although combat with skellies was a bit iffy. But it became easier once I got a few health upgrades. Good graphics for the type of game it wants to be, the bombs and digging were very satisfying.
But I, like others, could not find any of the crystals needed. I checked the map in the bedroom and I swear I dug in the right direction and blew up/mined half that quadrant but couldn't find anything. I eventually called it quits, but I really had fun for a while there with the digging and chaining bombs and using bomb mobs to clear walls.