Perhaps in an effort to be the prettiest Free To Play shooter on the market, Warframe is going seriously big on PhysX effects. You can watch Digital Extremes' new trailer - which is basically just unabashed eye candy of the most titillating order - below. Yes, that screengrab is gameplay footage.
Warframe is still in beta, but you can play it for free here. There's probably some hectic combat underneath all those particles.