Sure, thats true for the message their popping. But it also means the kill switch was in there since then. I guess it doesn't necessarily mean they intended to cancel it from the start though, if this is standard practice for all their apps.

I think the "kill switch" is that the server that it connects to when it boots up will be gone. It's not like it'll self destruct on the phone--you'll still be able to launch the app, it just won't connect to the server. Therefore, you won't be able to play.

The same thing would happen with, say, Draw Something, if a tornado came through and wiped out their data center. They wouldn't have built a purposeful "kill switch," it's just a de facto one because the server would then be embedded into a tree somewhere.