We are using Unreal Engine 4, but we have heavily modified it for our own tasks. It is more advantageous to work with something that is already well known and adapted to our needs.
The series has not avoided performance issues — especially Final Fantasy VII Rebirth. Larger open locations led to performance drops and image quality degradation on PS5, which prompted Square Enix to release updates. Similar problems also occurred in the PC version.
Even considering that a key element of Part 3 will be the Highwind airship from the original, it is still unknown whether the game will retain the same world structure as Rebirth. Hamaguchi clarified that the sequel will definitely not be smaller than the previous part, but he said this in the context of side content.
Given that the team is also working on a version for Nintendo Switch 2, Final Fantasy VII Remake Part 3 may receive better optimization. In the meantime, Hamaguchi and his studio have to finalize the port of Rebirth, which will be released in 2026.