Star Wars: The Force Unleashed

You can get this on pretty much any of the later missions. The returns to Raxus Prime and Imperial Felucia work very well.

You get Force Points (which are basically XP) for defeating enemies. The more difficult/stronger the enemies, the higher amount of force points you receive for defeating them.

I achieved this on the second level. Use lots of force powers to kill enemies and look in nooks and crannies to find 10k Force Point bonuses.