There was Rebellion, there was Force Commander, there was Galactic Battlegrounds, and now there is Empire at War.
Empire at War offers three single player game modes and two multiplayer game modes. The first single player game mode is the story based campaign where you play as a nameless and faceless officer in the service of either the Rebel Alliance or the Galactic Empire some time before Episode IV. In both campaigns you receive orders from your superiors either directly or indirectly concerning a story mission. The story missions can be done at any time, however; you're better off conquering all of the Rebel or Imperial planets open to you before you perform a story related task. The story campaigns are okay, but feel second next to the more free form game mode.
Galactic Conquest is the most satisfying part of Empire at War. In Galactic Conquest you can select from a variety of Campaign Maps that feature different settings: starting tech level, starting amount of credits, and the number of planets on the campaign map as well as objectives. Most of these settings can be altered in advanced options except for the planets that are present, and your campaign objectives. Galactic Conquest works in a way similar to the campaign (and 1998's Star Wars: Rebellion) in which you are given some starting planets, and you need to defend them with troops, vehicles, and fleets as well as conquer neutral worlds, Pirate owned worlds, and of course the planets owned by your opposing faction. If you have random events on you will also occasionally receive minor tasks, bonuses (or scolding as in the case of the Empire) from either Mon Mothma or Grand Moff Tarkin. Galactic Conquest also allows you to go head to head with another player in multiplayer.
Skirmish is the final game mode which lets you fight against the opposing side on a number of maps. Skirmish is a rather unique experience in EaW compared to most RTS games. In EaW skirmishes the game is always team based in which all Rebel Commanders are teamed together, and all Imperial Commanders are teamed together and share the same base. While this makes the game fit in better with the story; it can seem restricting, and there's still the problem of every Imperial Commander being able to summon their own version of every Imperial hero, and the same for the Rebels. Also, since there is no galactic map in Skirmish you produce units at either your land base or Space Station and summon them at a reinforcement point as is the case for land battles, or hyperspace them in; in space battles. Skirmish is the second game mode in multiplayer as well.
The graphics in EaW are a mixed bag. On one hand you've got the beautiful and detailed space battles, and on the other hand you've got blocky Stormtroopers on top of undetailed terrain textures. The graphics in the land battles are not by any means terrible, but they pale in comparison with the space battle graphics. One nice feature is that you can view both battles "movie style" using the "Battlecam" which focuses on random units\groups, and sometimes buildings that are performing the most interesting actions at the time. In space battles this is a blast; it's really nice to see empty space, and then see the front tip of your Star Destroyer emerge followed by the rest of it while is fires lasers at enemy ships that are being pursued by TIE Fighters and Bombers, or to watch Darth Vader cut his way through squads of Rebel troopers, and crush vehicles and buildings with the Force.
The audio is superb, the voice acting is for the most part excellent, and the sound effects come right out of Star Wars whether it be the laser blasts or the loud rumbling of a Star Destroyer's engines. The music is also excellent which combines the John Williams score from both the Original Trilogy and Prequel Trilogy with some new music by C&C Legend Frank Klepecki exclusively for Empire at War. There are some poor voice acting moments (The Stormtrooper that pops up in the GC mode to speak to you sounds nothing like a Stormtrooper, for example) the audio is a strong part of EaW.
After several honest attempts Petroglyph managed to deliver what Coolhand (Rebellion), and Lucasarts (Force Commander and Galactic Battlegrounds) failed to achieve; an excellent RTS set in one of the most loved sci-fi universes of all time. If you're a Star Wars fan you owe it to yourself to try Empire at War. If you're not a Star Wars fan it may not be worth it; most of EaW's best moments are those moments that only a fan of the Star Wars saga can appreciate.