Hi! So the ghost in the beginning prompts that you can continue on after you get the right answer. You just pass through the portal to the overworld. You missed so much fun content! I highly recommend that you give it another go. :)
Just replayed the game. I managed to reach 2 endings, one of them was the bad ending by the God and the other was a completion message after assembling a dog and finding 3 items. Nice idea to have multiple separate levels within the world.