In support of the New Game+ dungeon and Sindar Ruin connection, Suikosource user and dataminer JiN88 explored the Japanese demo to support the idea that Sindar Ruin underwent some major changes during development:

• In the entrance between White Deer Inn and Sindar Ruin, there are 2 statues that are generic. In the demo, those statues are gendered with pronounced breasts, and appear snake-like, resembling the Greek mythical monster Lamia. The generic statues exist in the demo, so there is no reason the developers would go out their way to make a different pair.

• At the last puzzle where you put the plate in, the plaque that you would normally read is there instead of in the room next ahead.

• The two statues of the Double Head are absent.

• In the boss room of Sindar Ruin, there is a weird sprite that isn't seen anywhere else (it's a bit grainy so to see it you will need to zoom in). The position looks like it's supposed to be for an arch, but notably it has three heads. Double Head is the boss you would normally meet here only with two heads, suggesting there was originally a boss here with three heads.