• Focus mode?

Turn off the HUD, cross-hair, mini-maps and interaction & navigation prompts completely throughout the whole game-play experience. Enabling this should deactivate all other options shown below.

• Navigation prompts?

Should you show on-screen prompts about where they need to go?

• Interaction prompts?

An example of what this is would be: "Press 'E' to use" appearing on the screen when you go near it.

• Waypoint markers?
  • Options for markers on mini-map on/off.
  • Options for markers in the world (like a giant arrow in the 3D world) on/off.
    • Could have distance fade in options for this when on.
• Mini-map?
  • Add opacity options for a mini-map.
• HUD Opacity
  • Could fade from one value to another when not in use.
• Cross-hair Opacity
• Options to fade out certain HUD options when they're not needed.
  • Allow them to select which parts.
  • Allow them to set timers for those parts (times after they're no longer useful).
• HUD size slider (makes it bigger or smaller)

References