I don't play this game yet so if your one and have a lot to share about his game please share your experiences in comment section. Much appreciated!!
Anyway here is what I found so far. It's a game about finding locations where you have to hack into and these places are called portals. And you can connect links between portals but finding these portals can be difficult as you have to go around places and it's not just a virtual game. It's interacting and you will consider yourself as an agent and doing your investigation about the invasion in our world.
One other post says "For those seeking an #ingress invite, #ingress is currently in beta testing and google gives invites as they will. Google will eventually open to all who want to get involved but remember it is not just about hacking portals, there is a story that goes with it and a mystery that needs to be solved."
This is one classic example for ARG - Alternate Reality Game, where the game involves real world into the game and the narrative story telling and the story changes bases on the gamer interaction and the actions.
Hope this ingress doesn't create some addictive gamer turning into some psychotic agent believing to be a real agent trying to solve the mystery and save the world and running around the streets of our world.
As you play more and more you will lose the difference between virtual and reality and could well be stuck in the abyss of agent world and become yet another "beautiful mind", just kidding, or am I??