Combat Mission guide: a guide to Battlefront’s wargame series It's big, ugly and startlingly expensive, but it's one of the deepest battlefield sims out there - here's how to get started The Combat Mission (CM) series stretches back some twenty years. On the surface it’s an unlikely success story. A deep tactical battlefield simulator with average graphics, a hefty price tag, convoluted patching system and availability through a niche storefront. And yet, like all great games, it is carried by its gameplay. For all its faults, and there are a few, it is still one of the deepest tactical battlefield simulations available. Consequently, CM has seen eleven separate releases, multiple expansions, and has kept its fans coming back to the battlefield for some two decades.