Treasure hunts and Open World puzzles make use of clever mechanics and layouts for players to unlock unique rewards.
The Tokai Sabuku is one of 4 fully customizable vehicles the player can unlock in the game. This one is found in a locked warehouse, and the player must find a way inside to unlock it from within and claim the vehicle.
The Long Drop is an Open World treasure hunt in which the player must recover the Storeroom key from an Unfortunate Engineer, which cannot be recovered until the Sluice gate is shut closed.