Alright for single player, Great for multiplayer
Firstly the space combat is a major new feature in the game. The controls for it are easy to learn and its wonderful flying around in space. But after a while it begins to seem ummm repetitive. You get one capitol ship and a couple of frigates and a whole lot of fighters and bombers. You can also man turrets and guard the interior from intruders and repair sheilds. Now it depends on which map you pick to whether the ships are side by side on head to head or just randomly piled. But on the whole its a great addition as long as you dont always play the same courses.
The second major one is heroes, its pretty simple get some points and you will get the option of a hero. But you can change the options so you can always have one. Anyway what hero you have avaliable depends on your side and the planet. So Republic playing on Kashyyyk will recieve Yoda. But on Mos Eisley there is a Assult game style that lets you play as either villians or heroes and it's basically n all out war between them. You will see multiple Vader's and such. Each hero that basically weilds a saber has two force powers (except for Mace Windu who recieves a ground smash force power aswell (jump and attack)) Some Jedi are the exact same as others but ah well. The other hero type is the gun weilding type such as Jango Fett or Han Solo. They are similar to normal units but have unique weapons. The heroes dont really have health but a timer in the shape of a saber that slowly shrinks and when you are hit you lose some and when you kill people you will gain some. So its a very smart idea to sit in a small area full of enemies just wildly swinging your saber.
Of course there are new planets mostly from Episode 3, the only bad thing is that the old maps are gone so on Naboo you will no longer be on the grassland but you'll be in a courtyard instead. And you'll no longer have some planets that have to maps, they all have one.
Next there the Galactic conquest. This is completely remade and much better. Instead of seeing only 5 or so planets you will see the whole galaxy with all the planets scattered throughout it with different routes. You have to buy new classes of units and bonuses. And you can also have multiple capitol ships flying about at once. And basically if your ship runs into another you will have to win a space battle, if you run into a planet guarded by a ship you will fight over the planet then proceed onto the ground map.
The new Campaign is good to, you follow the 501st legion's path from Republic to Empire and it begins a bit before Episode 3 and ends on the battle of Hoth.
So thats basically it, the gameplay is much alike to its predecessor with new bonuses and the single player aspect of the game will last you as long as you learn to easily beat the game on elite. But the split screen and multiplayer is what makes the game live on after the single player aspect bores you. Trust me its a hell of alot of fun to do crazy stunts up ramps and all with veicles trying to chase your enemy mate whos a jedi.