I love this game, it's really hard to put down once I get into it. I've only had a chance to play it for a little bit within the past week, but I think I'm already near the end of the game. At least, I think.
I bought the guide along with the game, but I'm not going to look at it until I beat it through at least once.
I only unlocked one extra costume so far, the sith robe that was on like.. the second or third level. I <3 that robe so much. I can't wait to see what the other sith costumes are. But it's so badass to look like a sith from the get go. XD Coupled with the Unstable Red lightsaber crystals... *drools* It's always nice to know you can look badass.
I had trouble with the bosses at first, but once you get the combat down you don't even need to target them except to use force push.. and even then you don't always have to have them targeted.
Still, I've not yet beat the game on normal mode. I'm digging the story enough so far, but I do wish the cutscenes were longer in order to delve into a larger story. Yet, even so, I'd say the story works so far.