As this game's lengthy title suggests, Renegade Squadron is just the latest in a long-running line of Battlefront games, which in turn owe a lot to the Battlefield WWII games. It's all about running around a virtual battlefield with different soldiers and their vehicles -- and is about as close to playing with Star Wars toys as you'll get in a video game, even more so than the Lego games. Claims that this is exclusive to the PSP are technically true, but remember that the same kind of game is available elsewhere on the PS2, XBOX, Windows, and Macintosh, in arguably better form (Star Wars Battlefront II).
The PSP already has a similar game to this, in the form of Star Wars Battlefront II (2005). That well-intentioned port pushed the PSP farther than it could go, with clunky controls, slow framerates, and local-only multiplayer, which was the kiss of death for a game primarily designed for online play. It still sold well and can be found cheaply, but Renegade renders it irrelevant. In single-player mode, Renegade Squadron is one of the first game to use the full 333 MHz of the PSP's clockspeed. In multiplayer mode, it drops to the usual 222 MHz to conserve power, but because of a few smart design choices, raw power isn't absolutely needed for a great experience.
What's new here? The biggest change is in the controls, which are greatly improved over the PSP version of Star Wars Battlefront II. When you're on the ground, you can holding down the R button to lock your sights on an enemy, letting you circle around him without losing your aim. While you're flying around in space (in X-Wing and TIE Fighters, as well as the Millenium Falcon), you can autoselect a target with one button, and pressing another will enable an autopilot to point you in the right direction. Since the autopilot follows lines of sight only, you'll still need to use your brain to maneuver the 3D objects in the space scenes. These changes are well-suited to the handheld, and while they make things easier, the tactical challenges are still present. I'd rather fight against my onscreen enemies than the controls of a game!
The other main difference between Renegade Squadron and the previous iteration on PSP is the inclusion of Infrastructure multiplayer. In other words, you can play on the internet with strangers, using a Gamespy-powered server explorer, much like the console and computer versions of the game. I didn't notice any significant lag when playing online, and there were plenty of opponents.
Other nice touches: the short (took me about 3 hours) campaign story is typical Star Wars, interwoven with events and characters from the films. You rescue Ackbar, you fake out the Emperor, and there's a lot of Han Solo fan service such as "Greedo shot first" in-jokes. Like most SW stories, it doesn't take many risks, except for the scene where you infiltrate the Emperor's home and smash up his holy relics, Taliban style. It's told with beautifully painted panels, which are partially animated (more than a pop-up book, less than a cartoon). Voiceovers and sound effects are of typically high LucasArts quality. Character customization is simple yet richly integrated into gameplay, forcing you to to choose the balance of health, firepower, speed, and other attributes based upon the needs of each mission.
If you've enjoyed other versions of Star Wars Battlefront, is this worth getting? In my opinion, the fixed controls and fully developed multiplayer makes this the best portable version of this kind of game yet. It can't compete with PC and console versions (with higher resolutions, better controls, and more robust online play with voice and keyboard support), but it's easily the best Star Wars game to come along since SWBF2. It's a great little game and if you're a Star Wars fan with a PSP, you should have it already. If you don't yet have a PSP, there's a white, slim PSP with a Darth Vader silkscreen packed in with this game, too!