Story: TFU 2's storyline isn't that bad but the main problem that it has is that it's pretty underdeveloped. Some characters(Like Boba Fett and Yoda) don't get enough screen time , some plot points never explained.(Maybe they wanted to explain in TFU 3 which was unfortunately cancelled)
Pre rendered cutscenes: They have improved a lot from the way they look in FU 1 and look like a CGI movie.
Gameplay: Force unleashed 2 is a hack'n slash game with some similarities to Psi Ops. you can jump , attack with lightsaber and use different force powers. you fight enemies, do some platform jumps and collecting some stuff(Like lightsaber crystals)
One of the things that people always criticized about FU is that the main character is overpowered which can easily be fixed by giving enemies handicap.(Like not using some pretty powerful force powers like fury and repulse)
In the terms of gameplay Force Unleashed 2 fixed some problems that FU 1 had:
1.Now Starkiller is much more faster and responsive.
2.Game is also faster thanks to some kind of Tech they used to make a 30 FPS game play smoother.
3.Game isn't as buggy as Force Unleashed 1.(Even the PC version of Unleashed 2 which had some bugs wasn't as buggy as unleashed 1 on consoles)
4.Loading times improved a lot and you don't have to wait in loading screen when going into menus.
5.Aiming has improved a lot compare to unleashed 1.(Which would make you grab some items that you don't want)
6.Enemies are also more diverse, in Unleashed 1 most enemies where just same enemies with different weapons but unleashed 2 made them with different kind of abilities.(Some are faster,some are immune to force so lightsaber is more useful here than unleashed 1 etc)
7.Challenges are also much better than unleashed 1.
8.Bossfight battles were here mostly due to better camera.
9.Force Mind Trick is a great addition.
10.Enemies will get body damages and from that you can realize when they are falling down.(You can also behead them here unlike unleashed 1)
gameplay problems:
1.Game is too short and on PC it's also shorter due to lack of Endor DLC mission.
2.It has some bugs.(Only PC version)
3.sometimes game just copy pastes areas which isn't that annoying for me but it can get annoying for some people
4.Story is rushed which I have already talked about it.
5.It needed some ranking system for levels which unfortunately it doesn't have one.
Conclusion:
Unfortunately Force Unleashed 2 is a rushed game , the development team of this game only had 1 year to make this game. The result is a sequel with better mechanics and force powers but with shorter levels and an underdeveloped storyline.
For me the PC version deserves 7.5/10 while the PS3 and Xbox 360 versions deserve 8/10.