I don't know what Godot or my PC is doing when your game is running but when I start up the game it runs perfectly fine, interact with a menu or two and is still fine, after starting to move around, FPS immediately plummets to 3-6 fps. Without exception. Tried changing around the display settings, even moved the game to another drive just in case. Nothing. Definitely not playable for me until something changes.
Hmm. This is actually the first time I’m hearing about something like that. There is one thing: if you have an AMD card with driver version 25.8.1 or newer, there’s some kind of incompatibility with Vulkan, so you might want to roll back to version 25.5.1 or switch the game to OpenGL. But people usually report that issue in relation to artifacts and crashes.
Anyway, I’d appreciate it if you could tell me what hardware you have.