This turns the game into something of a perfectionists dream - you'll end up doing your best to save certain units, unlike resource management games where sheer force of numbers usually decides the winner. Spanning 30 missions, the single player game will keep you occupied for quite a while. Once past that, you can jump into multiplayer by either the standard game or the 'drop-in' game, a sort of deathmatch. This is a pretty cool idea that brings some quick fix, arcade flair to the game. Since you're controlling squads rather than individuals, you'll often find groups of units crisscrossing to reach certain locations.
Friendly fire is a serious problem, and, while realistic, is a pain in the ass.
Watching a group of infantrymen run directly through heavy tankfire to reach a point is silly, and setting up waypoints while you're getting pounded by gunfire is hardly conducive to surviving. I also have a gripe with the air units. They certainly look cool, but they're hard to control and usually just end up getting shot down by enemy fire. Aside from that, the unit balancing is pretty good. Despite these minor annoyances, Ground Control is a blast.