The game has a very loose story, one of you the hero out to rid the world of demons. (justpushstart.com)
There's a very loose story in there about crystals - you want them, but you're going to have to go through a load of big old monsters first - but you could quite easily skip over the dialogue boxes without really missing a thing. (digitalspy.com)
A very loose story framework surrounds the world of Warframe, one in which players control members of an ancient race called Tenno who are tasked with safeguarding the Milky Way against various alien threats. (allgamers.com)