An old rusty key found deep in cave, what kind of door could it open ?
Explore a dense world, fight ferocious enemies and solve puzzles in search for answers.

Master key features :

• Item based exploration
  
• Dozens of enemies
  
• Shops, weapons and powerups
  
• Dungeons
  
• Between 5 and 10 hours of content
  
• Lots of secrets
  
• No language support!

The game doesn't hold you by the hand, it's a love letter to hiking and exploration, you have to find your own path and nothing is story-gated.