This article helps to shed light on just why Heartland got canned.
Whether or not you agree with Jaffe's views, this undeniably could have been an interesting take on an FPS.
Jaffe's cited a host of reasons why Heartland kicked the bucket, much of it stemming from Jaffe's fear of becoming involved in another game development time sink. Speaking to Newsweek, Jaffe explained Sony's mixed response to the project and how they hoped Jaffe would decide to make it for PlayStation 3:
"The game was very much a liberal person's response to the Bush administration and the war in Iraq. When I was entertaining lofty thoughts, the idea was to create an experience that would try to make the players--whom I mostly assumed would be of the Western world--feel what it must be like to have their own homeland occupied by another country."