Possible Clues:

• Mystery doctor in game
• Something mysterious and puzzling
• Puzzle set in game
• Cipher decrypted -- meaning navy's stood down
• Solution to mystery points towards decapitated old character
• Game in crackers is a mystery
• That's the problem of the image about the North
• Hard-to-know person
• Variation resolved in game
• It's a puzzle how one can have some gain with me