Thanks for playing. There is in fact a p2p multiplayer mode with voice chat/visemes/VRM avatar tracking which is what libmushi is (https://github.com/hiinaspace/godot-network-audio plus some other extensions), it's in the menu if you want to give it try with either other VR or desktop players. And https://github.com/TokisanGames/Terrain3D is what I used for the heightmap terrain. libphonon is also part of steam-audio, not sure why it's a separate .so though. I do really like HRTF spatialization in steam-audio in VR yeah, it adds a lot over the basic attenuation and panning in vanilla godot when you can move your head around and make little adjustments. It'd be nice if it were natively included, even if the other fancy steam-audio features like occlusion and probe baking aren't.