MILD SPOILERS
Oh come on, the Leia thing wasn't that bad. At least she wasn't dressed up in some nut job getup with 10 lbs of makeup on (what was with Episode 1 and everyone looking like a clown).
The games is fine but unpolished. The story is arguably better than the prequels even with the love story being fairly tacked on (the love interest is barely developed because she is a disembodied voice 90% of the time). To give them credit, they do a very good job developing her character while she is a disembodied voice. Her tone and chatter noticeably changes over the course of the game. This isn't like Jan from Jedi Knight II where you are thrown in the middle of a marriage and just have to go along for the ride. I'll forgive them for the overall cardboard cutout of a character even though it was used as a primary reason for Starkillers redemption because hey, at least it wasn't as creepy as Padame and Anakin (really, think about that relationship for a second *shudders*). That being said, a few Star Wars characters were actually developed better in this game than in the movies. This really helps you make sense of the III to IV transition if you care about that.
The story complaint that was given for this game in some reviews was how it wasn't branching (and even one ranking it lower than Jedi Academy). This is somewhat amusing. I really would like to know what game these guys were playing. In Jedi Knight II you had the same disembodied voice love interest who didn't develop at all because she was presumed dead 90% of the game. The game also had no branching what so ever. I won't say The Force Unleashed is a better game than Jedi Knight II (lets admit it, both games suffered from repetitive enemies with "harder" ones thrown in where you had to be somewhat cheap), but I won't say that one story is superior or more engrossing than the other. Now then, on to stealing candy from a baby. The Force Unleashed makes Jedi Academy really look like an after school special now. Your motive for going light or dark side at the end is real. Your choice is telegraphed to you through the entire game and you really do see Starkiller come to grips with this during that time. That in mind, this isn't Mass Effect. There are no dialogue trees yet they manage to setup the choice without making it contrived (hey Rosh, I think you're a jerk so I'm going to shove this lightsaber into your back and then go kill a bunch of Jedi for kicks). You won't really feel conflicted like some of the choices in Mass Effect may have made you feel (no executing an unarmed person by shooting them in the back of the head moment) but then again, this is Star Wars where everything is black and white.
Moving on to stuff more specific to the Xbox 360/PS3 version, the quick time events were not that bad. Some of them were difficult because of the lack of prompt in the beginning of the event but otherwise there is a slight slow down of time that you will notice before a button prompt. That being said the event where you pull down the star destroyer is horrible and they honestly should have just made that a cut scene instead of make us live that god awful moment in game. Starkiller is not an X-wing.
Other than that, the game mechanics were fun if not a little trial and error based. There are prompts given in the beginning of the game but they don't really prompt you in any meaningful way other than "this thing is glowing blue." The prompts get worse and worse as time goes on. I don't know if this was meant to increase the difficulty of the game as a physics puzzle solver or if they just ran out of time. Either way it isn't really that great as a puzzle solver as the DMM is used so sparingly it might as well have been "faked" physics. This is a technical limitation, obviously, and hopefully the next generation solves this problem. That being said, they definitely left a couple loose threads for a sequel (more major spoiler if you think hard: who is left standing at the end kind of leaves a huge opening for a sequel to happen a few years down the line).