browser game has to work across network conditions and devices, not just on a fast desktop. For fallback policy, test the first useful frame, interaction readiness, and fallback behavior separately.
For browser game, test slow loading, unavailable 3D support, keyboard or assistive input, and disabled analytics. The fallback should still communicate the product or scene clearly.
Provide a useful poster or static view for unsupported devices, failed loads, reduced-motion users, and slow connections. Apply this fallback policy guidance to the actual browser game delivery path.