It's a bit hard to tell what to do in this game. What is my goal? Were should I go?
I like the sound and look of the game. Good atmosphere.
Fighting the ghosts is an issue though, they come from all angles but I can only shoot side to side. It's not impossible, but it's more frustrating than fun right now. They also seem to disappear for some reason, and reset their positions kind of randomly. I don't know if that is a bug or some unexplained mechanic.
Taking damage will reduce hearts, I can see that. But I think it would help a lot to give more feedback to the player. A sound indicating getting hit, maybe a bit of a small explosion where the projectile hits, screen turns red for a split second... These help a lot in conveying what is damaging you. More "juice" would help a lot.