Thanks for contacting me via the Discord (https://t.co/VVRd14Nb3P for those interested!). It seems like you ended up with a weirdly broken build (your first encounter was a completely empty map with no exits). I've successfully tested a version by extracting directly from the zip file on this page as you described, but for the least hassle I recommend the Itch.io app (https://itch.io/app) for installation and patching of the game. It handles installs and upgrade patches really smoothly and don't worry, you don't need to keep it resident like Steam!
Everyone: Please let me know either here or on the Discord if you run into a similar problem! I'd like to deal with it as completely as possible.