I love the atmosphere of this game! It's somber, but not sad. Dark, but not grim. Reminds me a bit of Castlevania if it was puzzle based instead of combat based.
The mechanics are solid, and fit the theme very well. Also this might be a hot take, but I disagree with people saying the ghosts take too long. Watching the ghost make all the mistakes you did makes you contemplate how the mechanics work, and what can be done with them. It teases you with the idea that if you whiff a jump, you'll be watching yourself mess it up again, and works as a motivator to nail it the next time. It gives me a bit of a speedrunner mentality that I want to try to make the most efficient run that I can, and that every life in the process matters.
Overall it has very few issues, and a lot of great things going for it! Well done!