All the assets are from the GDevelop asset store: The Sky Background, graveyard background grass tile, wall tile, tree, and everything else. I just drew the "jail" in Piskel.
I create my 3D assets in Blender. I am not good at 2D though. I will try someday. Thank you. You are a good artist, I visited your profile. All the best. I created an asset (Jail) in Piskel for the first time.