Warhammer 40,000: Squad Command is a strategy game that puts you in control of a squad of six Space Marines. The actual plot isn't very important, nor is it clearly presented. Everything is presented through a series of still images and wordy explanations that never draw you into the game, nor give you any context as to why you're fighting in the first place. This isn't important in the long run, since all you really need to know is that the Chaos forces are the guys you need to shoot at.
Mission objectives are straightforward and easy to follow. Before each mission, you can survey your goals which, in theory at least, should influence the weapon load out for your squad. Though you can do this, I typically found a setup I liked and stuck to it, regardless of mission type.
Gameplay is based on command points. Each unit has a set number of points that can be used for either attacking or movement. Each step takes away a set number of points, so the longer the travel distance, the more points he'll eat up. Attacks work in a similar manner, though pumping points into your attack increases the weapon's accuracy. Command points add an almost Chess-like component since you'll sometimes have to think 2 - 3 actions in advance to make sure you have enough action points. Before ending a unit's series of actions, you'll also have to decide if you want to use your unit's Overwatch ability. When active, units will shoot any unit that moves into its line of sight. When used effectively, this can really limit your opponent's options. At the same time, it can also limit your options and become a bit of a gamble since there's no guarantee that enemies will move the way you think they will.
Multiplayer is available using local, game sharing and online options, though each generally boils down to the same gameplay type - kill the other guy. A number of different map sizes are available, at least online, though finding an online match was tricky.