That was really fun! The mechanics are competent and polished. The monsters all have a clear pattern and method. The art and character design is exceedingly charming! The soundtrack is nice and spooky. All-around, just a great game!
That was a cool GBJAM 12 splash screen!
With all due respect, I'm not sure why the object opening sound rises in volume until it's quite too loud. Having it rise in pitch is a great indicator of progress; having it rise in volume is an obnoxious effect that messes up the audio balance. Also, the opening sound can stack on top of itself when opening multiple objects at once, making it even louder.
All-in-all, great work!