This is not yet a full rust implementation.
xgameruntime.gdk.dll is the official gdk sdk .dll renamed and needed for this wrapper to work.
You find the original xgameruntime.dll inside of the 2604 sdk installer PC Development.msi Microsoft GDK, you can use msiextract under linux / macOS to get this without windows.
To use Xuser with Minecraft for Windows, you currently need to follow this PR description to patch MicrosoftGame.config until XUser is generally available.