Combat Mission is a 1-2 player, turn-based, simultaneous-execution 3D simulation of WWII tactical warfare. It combines unparalleled game depth and ease of use with a true 3D environment. The move to the 3rd dimension is not just to look cool, rather it it improves the accuracy of the simulation. Think of the world around us - it's all 3D. True 3D LOS, 3D spotting, 3D terrain, and 3D trajectories are a lot more realistic than 2D approximations, so that is what CM delivers!
Source: The Publisher Website.