Thank you
>Do you plan on adding more content in the future
I'll decide based on the project's response. I'm not really keen on it.
>I’m not sure if it would be okay to share a modified version of the game.
Modifications, commits, and redistribution are highly encouraged.
However, since this repository contains portraits of clearly identifiable individuals other than myself, copyrighted VRoid models related to Pixiv, free sound effects, and other such content, I must refrain from granting an explicit license for the entire repository.
(One could even argue that publishing code containing such assets on GitHub is inappropriate in the first place!)
That said, I do not anticipate any particular issues arising, and I personally have no objection to others forking or sharing it.