Zero Hour: America's Medic is not yet available for purchase. The game is complete and it is currently being integrated into an e-commerce and learning management system managed by George Washington University. Due to some early press coverage there has been an overwhelming interest in this product resulting in the need for load/stress testing of the systems prior to launch.
The official word is 'fall 2008' for an anticipated release. Please check out the following two URLs for more information, announcements and downloads:
http://inside.gwumc.edu/nemspi/ (this is where the game will launch from)
http://virtualheroes.com/
Best,
Jerry Heneghan
CEO, Virtual Heroes Inc.