Opening Ideas

The game starts with a house in flames, with the caretaker in the arms of Karrah. He briefly instructs Karrah on escaping and finding his hidden lab so that she could learn the truth about herself. The hidden lab is where we'll find all of her caretakers important research, notes, specimens, and living creatures roaming around with jars on their head, and bone collections (Karrah finds her weapon here).

The hidden lab, will have its own secret route to the mechanism that he made for traveling back and forth to the forbidden place. As we progress in the game, we end up learning that the house was set on fire by a dangerous religious group known as Nirmata, who believed Karrahs caretaker's ideas and research to be a threat to their interests and the society that they live in above. So we're starting the game with a sense of urgency and at the height of a big event.

Like a traditional Metroidvania, there has to be something early on while exploring the Forbidden place that is inaccessible and gives us a reason to travel back up. At that point, we would have unlocked town exploration. But the beginning of the game should be laser focused on Karrah.