Unity Project Settings Checklist

Set Color Space (Player → Other Settings) to Linear only if your target GPUs support it; stay on Gamma for older Android devices.
Enable per-platform texture compression (ASTC for most modern devices) rather than shipping uncompressed textures.
Set Managed Stripping Level to Medium or High to cut unused code from the final build.
Use the IL2CPP scripting backend with ARM64 — required for the App Store and Google Play.
Cap Application.targetFrameRate explicitly (usually 30 or 60) — uncapped mobile builds drain battery and thermal-throttle.
Review Quality Settings: reduce shadow distance and cascades for lower-end tiers.

Set Api Compatibility Level to .NET Standard 2.1 unless a plugin specifically requires .NET Framework.
Use IL2CPP with the Master C++ configuration for release builds — faster at runtime than Mono.
Confirm Quality Settings has a sensible default tier for the build target, not just the Editor’s tier.
Turn on Static Batching and GPU Instancing for scenes with many repeated meshes.
Verify V-Sync and target frame rate match what you actually want shipped, not Editor defaults.
Set Fullscreen Mode and default resolution deliberately; enable Resizable Window if you support windowed play.

Enable Brotli compression under Publishing Settings — this alone can cut build size dramatically. See the estimator.
Set Managed Stripping Level to High and enable Engine Code Stripping to shrink the download.
Set Enable Exceptions to None (or Explicitly Thrown only) for smaller, faster builds unless you need full stack traces.
Use Addressables to defer loading of scenes/assets instead of bundling everything into the initial download.
Check Decompression Fallback if you can’t configure server headers for compressed files.
Test actual load time on a throttled connection, not just localhost.

Lock to the headset’s native refresh rate and never let frame rate dip below it — dropped frames cause motion sickness, not just visual stutter.
Use Single Pass Instanced (Multiview on Quest) rendering instead of Multi Pass to roughly halve draw-call overhead.
Use the OpenXR plugin rather than legacy per-vendor XR SDKs.
Keep draw calls and triangle counts within your headset’s documented budget (Quest budgets are far tighter than PC VR). See the budget calculator.
Bake lighting wherever possible — real-time shadows are one of the most expensive features in VR.
Profile on-device early and often; Editor frame times are not representative of standalone headset performance.