Long story short: More good than bad, worth getting. Full review for details (warning, LOOOONGG!)
Most of you will know the basic plot but I'll just go ahead and say it anyway. Vader basically has this secret apprentice named starkiller and he just sends him on varous errands, mainly killing the last of the jedi.
Lets just get the bad things out of the way first. If your getting this game, these are the things you will face.
- monotonous combat. yes its great fun in the early on but once your past around the mid point, things start grinding to a halt. Enemies are artificially made stronger by increasing their health bars. An enemies' block is nearly unbreakable save for a few guard breaking combos. A huge combo finishing off with a huge (i stress huge!) explosion of force lightning will not even damage slightly a guarding opponent.
- no camera control. The devs took the god of war route and made the game operate without any means to manually control the camera. Only difference is they used a proper 3rd person perspective that simply doesn't work without occasional manual control. But luckily I hadn't experienced many instances where this is a major problem.
- crappy bosses. Bosses just don't really have any strategy in them. It doesn't play out like a fighting game or anything, there isn't any particular method to kill each boss like in shadow of the colossus or zelda. You just have to work out a system. Before I knew what i was doing, I died 3 times playing as vader at the beginning of the game! You'll learn to just rely on cheap guard breaking combos and then force lightning whenever they aren't blocking. Even then it takes like quite a long time but it gets the job done.
- major frame rate issues. Its not like a lagging video. It plays perfectly fine for a while and then it will freeze for a full half second before continuing for another 30 minutes or so. It doesn't happen consistently but when it does happen its pretty bad.
- 7-9 hours long. Its another god of war! well almost. It is slightly longer but come on, 8 hours isn't that long.
OK. On to the good. So yeah, it has a great story. Following starkiller on his adventures and seeing the outcome is definitely satisfying and the overall story I would say is a step up from the prequel trilogy. If your a starwars fan, this alone is worth the purchase.
The game has brilliant art direction. Planets like Raxus Prime and Felucia are just genius. A junk world and a crazy overgrown world teeming with life. Thats awesome.
And the graphics are amazing. As good as god of war if not better. I'll go on to say that the force lightning in the psp version is more satisfying to watch than in the next gen consoles. Player models are EXCELLENT and everything animates nicely. Did I mention all cutscenes use the in game engine??
The whole game just plays really nicely. Your attacks and combos feel really powerful. It has some ragdoll physics working for it when you throw people around. But zapping them with electricity gives preset animation.
There are lots of unlockables. From different light saber colors to alternate costumes to concept art. The game is a complete package, just maybe not a well polished package.
And yes, there is new game "plus". Which means you can play the game multiple times with your same beefed up character from the previous play through.
Overall, I'd say go buy it. Story is great and the graphics are amazing. Sound is just what you'd expect from a star wars game. Definitely gets kinda boring towards the end but still worth a play through.