Running the original Half-Life on Android via Xash3D is legal if you own the PC game files. But you cannot legally run Black Mesa’s assets this way, as they remain copyrighted.
Using a file manager, copy the valve folder from your PC’s Half-Life installation (e.g., C:\Program Files (x86)\Steam\steamapps\common\Half-Life\valve ) to /sdcard/xash3d/ on your Android device. black mesa android apk updated
"I’m at the perimeter," Elias muttered into his throat mic. "Drop the package." Running the original Half-Life on Android via Xash3D