I'm not fond of violence but this full version licensed video game freebie today (and cheap other days) seems like it would appeal to a lot of gamers. I think it might also interest students who have learned or are learning about historical battles. Perhaps as a treat for a homeschool project well done.
Here's how they describe it: "Arcanorum is an epic fighting game. Once you get the hang of its physics and the control of your upgradeable steam machine, you won’t be able to stop!
Control a flying contraption and swing the attached weapon around to destroy your adversaries. Earn cash and upgrade your ship as you complete missions, or battle waves of enemies in the survival mode."
You can download your copy here: Game Giveaway of the Day. Today: Arcanorum (for Windows and Mac):