Top notch simple pixel art and good core gameplay loop. As others mentioned, the ghost's unpredictability meant that sometimes I wasn't certain how it would move and why I got hit. This lead to some "cheap feeling" deaths and a difficulty curve that felt a little off.
I know it was probably frustrating for some people, but I liked the obscuring of important things by dark in this case. You left a clear message in the tutorial to look out and search for hidden things, so I was looking. An alienating choice possibly, but I liked it!
Great example of how a simple art style can go big with a little atmosphere! Great job.