Extremely low. It runs on most modern PCs with just 1GB of RAM and 600MB of storage.
If you own the original 2013 English release, JAST USA provides a free update patch to upgrade your game to the remastered version with improved engine and resolution. 🕹️ Where to Get the Game The Song of Saya Free Download
You can stream or download the haunting Saya no Uta Soundtrack for free via the Internet Archive . Extremely low