Ok, I used this with 2nd year Middle School girls. It was a great 'extra' lesson to re-sync my timetable (my classes get out of step sometimes due to exams or other timetable changes).
Anyway, the material was pitched at about the right level, and the game was fun. They liked the scoreboard (and, as a programmer, I appreciated it too). As well as showing the PPT material I tried to elicit as much as I could about WWI, but they didn't really know that much. Still, I was very impressed at how much they remembered from the presentation when we moved on to the quiz game.
So, thank you very much for sharing!