Like aesthetics and controls of the game. Some niche problems tho:
1) Resource indicator for coins is not clear enough. I'm using coins to buy upgrades for my ghost and at the same time I use coins to traverse through dimensions.
2) Placement of both portals is a little weird, because sometimes I enter wrong village. I suggest placing them more separately
3) Ghost Energy regeneration in safe zone could be a lot faster.
Otherwise, I really dig your idea. Upgrades are cool.