Art is wonderful and I love the secret levels. Fun callback to Mario! I couldn't figure out if that other ghost was referencing something, but the moveset felt similar to Samus, so maybe that was it? Anyway, lots of fun!
The other ghost was just a ghost of a generic miner. You also missed secrets in the first 2 levels. I’m planning on updating the game after the jam ends by fixing bugs, rewriting some of the mechanics and adding new levels