Star Wars: The Force Unleashed II

As metalanda7x stated Terror Trial is by far the easiest mission to platinum. I recommend having Lv3 Force Lighting and Lv3 repulse when doing the challenge. I would repulse all the droids and when a terror trooper showed up I would just run around in a circle tapping force lightning to shock all of them. Then its just a matter of using your lightsaber to finish them off quickly. I was able to platinum the trial my first time and having about 13 extra seconds until dropping to a gold medal.

I found the easiest to platinum was the kamino drill grounds trial.
you need level 3 saber throw then when the stage starts clear all the explosive barrels so that your sabers dont target them then just guard 2 of the doors and dash back and forward saber throwing the enemies, the sabers will seek out the enemies and you will easily make the 4:00 minute mark

Here's another challenge that takes a little practice, but is not bad to get platinum on, Retrieval Stage. After a couple of times practicing, I was able to finish at just a hair over 37 seconds.

If you leave a negative vote, please state why...

There is one of the trials that is completely easy to where alot of people have gotten a platnium. I believe it is called the Terror Trial. Use Repulse to take care of the droids and use mind trick to take care of the Terror Troopers so you can actually hit them.

i got this one on the Gauntlet trial, where you have to fight your way through several waves of enemies.

For this i reccomend having saber, throw, mind trick and repulse to level 3.

at first glances this seems a fairly tricky one to get through as you have to defeat, a carbon droid plus riot troopers, a terror walker plus jet troopers, a fire droid plus snipers and finally some sith acolytes plus terror troopers.
For the first wave, just mind tick the riot troopers so they kill each other, or repulse them out of the way then just got crazy with your lightsabers on the droid.
Second lighting the jet troopers so they start flying around. then to deal with the terror walker use fully charged lightsaber throws, if your lightsaber throws at lvl 3 then it takes about 2 maybe 3 goes to kill it.
Wave 3, mind trick the snipers and then same again charged sabre throw the fire droid. just watch it doesnt get too close
Final wave, just lightning/mind trick terror droids then use A+X combo to grapple and instantly kill them, same with acolytes.

i managed to get so i had a good minute to finsh off that last wave. its jsut a case of keeping your distance form the fire doid and terror walker and using the throw.

If you think ive missed something, have something i could change, have a better way to beat a wave or anything please comment so that i can improve it. thankyou.

Just in case anyone is struggling to get this achievement through other suggested means, here's a video that may help, instead of using the terror trial this one uses the domination one where you have to protect the centre for up to 55 seconds.