Complete the game with only 4% of items (Flashlight, Backpack, Grenade, Foam, and Missile).
Reach Level 30 to unlock infinite foam, which makes challenges like the Minimalist or Insurgent runs much easier. Shadow Complex Remastered
For those looking to fully master the game, aim for these specific badges: Complete the game with only 4% of items
Beyond opening doors, foam can be used to create platforms or bridge gaps. You can even stick grenades to foam to hit awkward targets. Shadow Complex Remastered