Treat mobile as a primary control and performance surface.
Controls
Provide a clear movement control, reachable primary actions, target selection, cancel/reset paths, and non-drag alternatives for inventory. Keep controls out of unsafe areas, avoid overlapping action zones, and show feedback for held, unavailable, and queued actions.
Responsive HUD
Design for representative portrait and landscape viewports. Keep vital status, target data, inventory, tooltips, and dialogs legible without covering the playfield. Support orientation changes without resetting gameplay state.
Performance and QA
Use device-appropriate quality defaults and adaptive decorative effects. Test touch targets, multi-touch, long sessions, audio unlock, pause/background return, reduced motion, low-end quality, and actual mobile-size viewports in the repository-approved browser.