I am the head moderator for this game's community Discord server. Pizznazz, the creator of the game has been out of contact for 2 years at this point, and I have received tacit permission to develop a spiritual sequel based on her original work. I have also sent a message to ask if I could continue her work directly, using the notes that she shared with me.
I have no received word back at this time.
Edit: Pizznazz has reconfirmed the blessing for me to build a sequel/successor, but will retain the right to continue FI at her discretion. This is understandable and preferrable. A separate post with my game will be made when it's available. I will always support Pizz's work and directions.