I was thinking about the 3DS's puzzle swap and how cool would it be to give only 1 person a certain piece, and then track the spread of that piece over time. Naturally, I started thinking about how awesome it would be for a player to watch something they designed spread over the world, and I wondered what sort of game would be able to do that. The best idea I had is spreading a virus, either computer or biological, through every streetpass.

That brings me to actually designing the gameplay. Because the game needs to resolve who wins and infects the other player's 3DS within a single streetpass, a player's role in the game is limited to preparing their defense and offense (somehow), but they can't influence the result beyond that (this is what I am referring to as fully asynchronous gameplay- let me know if there's another name for it.)

I can't think of any other games that have this type of gameplay, but can you think of a game that had it (or something similar), and what they did well/poorly?

The closest games I can think of are the multiplayer tower defense games, where a lot of the work is done between rounds to choose which units to send and which towers to build. Other games with similarities are CCG's, where a large part of the game is how well you build your deck. The problem there is that watching two AI play your deck isn't going to be very engaging. A last type of game that I can think of are those like The Castle Doctrine/The Might Quest for Epic Loot, where you build up defenses and then have no further say in what they do. These games (especially TCD) offer the rewarding type of defense building that I'd like, but their "offense" relies entirely on player input.

I'm not sure that a game about spreading computer viruses to other devices would be well received. People might get the wrong idea about what's really happening. You'd have to make it very clear that these "viruses" can't actually do any harm to your computer.

Would the game play necessarily have to be combative, with elements of offense and defense, or could it be more social and/or cooperative? For example, one idea you might try would be a kind of virtual pet where the goal is to raise and train a simulated animal. These pets could meet in a park where they interact with other pets that were downloaded online, or via StreetPass, or whatever. The player can either praise or scold the pet's behavior which would feed into the learning behavior algorithms. Players would have the option to train their pets to be either well-adjusted and friendly, or vicious and anti-social.

Actually, your virus idea could fit into a game like that. Everyone knows you need to vaccinate your pet otherwise it might pick up an infection from the other pets in the neighborhood.

Yeah, I liked the idea of a virus because it fits so well thematically with "infecting" 3DS's you pass by, but, like you said, it could fit so well to make people worried it's actually happening =P

I was thinking of the game being competitive for 2 main reasons- first of all, it helps slow down the exponential spread of the virus (or whatever is being passed). A 3ds would only be able to be infected by one virus, any new viruses would have to defeat that virus in order to infect the 3DS. The second reason is similar; a player would feel MUCH prouder of seeing a heatmap showing their "virus" is on 3DS's across the world if they knew it was because their "virus" was better than every one of those 3DSs', rather than just being the natural result of spreading over time.

(I'm a bit tired right now, so I'm not sure how much sense those sentences make- If you don't understand something, feel free to ask)

But yeah, you could make a cooperative game that uses streetpass to help and affect other people's games (similar to the built in streetpass games, but with more interaction between the player's games). I just don't think it would be able to capture the "my creation is spreading over the entire globe!" feeling that I'd like the game to give.

Oh, and I'm still open to any examples of games that have the fully-asynchronous gameplayer, or something similar.