First things first; this game is fun. It's fun, has tons of fan service, and despite some of the fairly contrived mechanics, it does a good job of putting you in the Star Wars universe, thanks to the use of sound effects right from the movies.
With all that established, this is a very hard game to really stand by or defend.
Before going into it, I had heard that Galactic Battlegrounds was very much like a mod of Age of Empires 2: The Age of Kings. While most reviewers mentioned this in terms of mechanics being similar, I found that this extended to the overall quality of the game. Animations are, quite frankly, poor, the sprite work in general is not nearly as refined as its inspiration, and sound runs into a lot of trouble. Overall, visual and audio execution honestly does not exceed the level of quality you'd find in a mod. A great mod, to be sure, but not a product made by Lucas Arts of all companies.
The quality issue extends to a few oddly done parts of the game itself. Jedi/ Sith Knights and Masters are listed as different units, yet functionality wise are identical save for the latter's improved stats and additional ability to convert things (AOE monk!). It would have made more sense to have the Master be the last line of progression for the former, but for reasons unknown, they are split. Another oddity, this one to do with presentation, is how Carbon rock formations are labeled as Red, when in fact they are visually covered in Blue. It leads me to wonder if this wasn't some massive typo...
The game also sticks to Age of Kings gameplay steps in ways that don't really fit, and go a step further in that they are almost lore-breaking. Because Age of Kings requires gold mining, over here we have "Nova Crystals, which are a form of currency". I'm a long time Star Wars fan, I grew up on all the books, many of the games, saw every single movie, and not once had I ever heard of a Tiberium like crystal being used as currency. But here we are, mining not-Tiberium and acquiring it via the use of Jedi/ Sith holocrons as tourist attractions (?!).
Despite all this, the game does have at least three noteworthy ideas of its own. The addition of Power Cores requires you to spread out your base, by leaving buildings to function at roughly 25% efficiency unless they are built in the radious of a power core. Similarly, Shield Generators can also be built to give structures and mechanical units a layer of rechargeable protection. This means that when attacking an enemy base, you'll want to prioritize your targets in order to deal the most crippling blow rather than knocking out a couple of random buildings. Finally, air units add a tactical layer that, while not perfectly executed, is still fun to play with.
As noted in the beginning, Galactic Battlegrounds is fun. But it's largely fun because the game it copies so directly is fun. Anything more than that, you'll only get if you're a big time Star Wars fan. AOE 2 HD is a largely superior game point by point (and quality wise), but this will make for some nice goofy fantasy exploration if nothing else.