As a little kid, I was a huge fan of World War 2 history, especially the weird stuff. When I saw the trailer for this, and that there were jetpacks, weird tanks, experimental aircraft, I about lost my mind. Nostalgia gives this a 5.
Holy mother of atmosphere. Played it mostly as a kid and never knew there was even a soundtrack, as I never had the play disc in...really colored my experience and made the game much more menacing. Had a tremendous impact on me.