The game *is* finished, but the final ending puzzle was literally completed in the last hour or two of development so the clarity on what to do isn't great. (SPOILERS) it's reachable after collecting 3 parts, checking the bottom left cave for hints, and then using the knowledge gained from the apple quest. The Pink Head is set to fall asleep after a certain amount of time passes, but extra work could've been put into making this clearer as well. (SPOILERS END)
Thank you very much for the kind words and feedback! We were actually discussing a potential remake, so it's very possible we'll have something in the coming weeks. - STEVE