yeah online is free, but the campaign is one of the worst i've seen its kinda fun and stuff first (especially space assault thingys) but then campaign is simply capture all the control points and hold em for 10 mins or something.
and in one of the levels u have to plant this bomb under some ship (being vaig no spoilers) and protect it, theres like 20 enemy spawn points around it and u kill one 20 spawn and ur guys are all at ur spawn 20KM away sitting drinking coffee, u die they shoot the bomb and you lose. but its not real tough on system requirments, on my friends laptop 9700 radeon mobility ran fine with 1.7Ghz processor.