I played your game and wasn't sure if I was doing things correctly.
I was able to clear the shovels and forks in the first section and gain ghosts. Then when I went to upgrades I wasn't able to purchase anything, but was able to set two skills.
I wasn't sure what the skills did or how to use them.
I defeated the first boss and then gained some of the second resource. I clicked the skill button and this decreased, but I wasn't sure what it did.