Game idea - Episode 1 (possible multi-episode)
You control a single main character in the game going through normal life with point and click mechanics (mouse or touch) to move your character around the game mostly in a 2d side view. The game would have limited options in each screen (not necessarily highlighted options but player can find them with trial and error clicking). The player is mostly guided through the game with easy to find actions that progress the game and story. The player isnt introduced to the main characters background and has to play to find out more.
Each time a cryptocurrency payment is made in game on the players screen (not just your characters payment but other NPCs too) a puzzle appears that’s symbolic of the transaction being validated. The puzzle is the main gameplay feature of the game and is fun and engaging. Most of the time that means the player is encouraged to stay in a room for a longer time to solve more puzzles by NPC customers making payments. The player can stay in a room longer while still progressing the game by buying things, sitting down to drink coffee, etc.
In many cryptocurrencies (e.g. btc, eth, etc) the puzzle reveals information about current holdings and previous transactions. For Zcash shielded transactions you can see a transaction ID but nothing else. When the player successfully solves a puzzle that transaction is highlighted in a tree view of blockchain transactions (on the players palm device).
Over time you start to see the same people again making more transactions which gives you more insight into the NPCs life. This slowly allows the player to start inferring other transactions that may have come from the same NPC (e.g. they often buy a coffee at 3pm) and build up a story of their life. Eventually when you get enough transactions for an NPC and you successfully identify unseen transactions occuring from the same NPC you start to see flashbacks of events and payments they’ve made in the past.
Weirdly as you discover information about their transactions it’s almost like other NPCs discover this info too. The lack of privacy starts to affect the NPCs in-game.
Comedic consequences:: An NPC buys flowers then accendently drops them and loses them to a dog. His partner noticed they bought flowers but never gave them to his partner and accuses them of cheating.
Scary consequences: An NPC has been following around other NPCs. By using the blockchain the NPC is able to identify when when to visit laundromat to be there at the same time as someone they are stalking.
As the stories play out Zcash isn’t key to the stories but the player does learn early on and on a regular basis that they are unable to progress the game by solving Zcash puzzles since they don’t gain any other information other then a transaction ID which can’t be linked to other transactions.