Too much like Age of Empires for its own good.
There is no real consistant storyline in Galactic Battlegrounds to speak of. There are a few campaigns that follow certain characters through "historic campaigns" a lot like the AoE series. Each campaign features a different plot and is in no way connected to the other ones (directly anyway).
The gameplay in GB is exactly the same as the AoE series right down to the lack of any real difference between the factions. There are fishing ships, a form of farms, droids picking berries from bushes... it's all here. This may be a Star Wars gamer's fantasy come true if they loved Age of Empires, however; the slow paced gameplay and the utterly bizzarre fact the droids require food to be built, and that they have to chop wood is a turn off for me. GB feels more like a large AoE II mod rather than a professional Star Wars game since the developers didn't seem to try to alter any gameplay elements. In GB you're still required to advance through tech levels (known as Ages in the AoE series) to upgrade units and research new technology to advance your faction, and increase their power.
The graphics in GB are both similar and different to those in AoE II. The unit and building art is of course more sci-fi, and more unique between factions compared to the AoE series. The forest maps look like they were taken right out of AoE II, however; fortunately most of the map tile sets seem to be somewhat original. This doesn't change the fact that GB feels more like an AoE II mod, however.
The audio is satisfactory; there are classic Star Wars blaster sounds and explosions as well as decent voice acting (though some of the character stand ins sound lousy; especially Lando, Han and Leia). The music is taken from both the original trilogy and Episode I, but I personally turned the music off since I got tired of hearing Duel of the Fates every time I started a new map.
Galactic Battlegrounds is suitable for Star Wars fans or general RTS gamers who loved AoE II, but at its core it is nothing more than a glorified mod, and quite frankly the AoE II engine doesn't mix well with the Star Wars settings. At least not a version that is barely modified at all. Try the demo if you must, but if you've played Age of Empires II then there's nothing to see here.