Thanks! Yup, this is all solo.
For the most part, yes. There are modified tiles from existing commercial tilesets such as Modern Exteriors and Horror City, as well as a lot of custom tiles and sprites. All of the artwork (characters, enemies, mysteries, etc.) is my own hand-drawn art, and anything I need to sprite/tile which I can't create by modifying an existing tileset is drawn from scratch as I go.