The story of "Lost Planet" is about EDN3 (believed to be the third "Eden" – the third attempt at terraforming an alien world) and the struggle between the company who is trying to terraform it, NEVEC (short for Neo Venus Construction) and pirates who are trying to steal the natural energy resources that have been uncovered there.
They work and fight in large "mech-type" vehicles called VSs (Vital Suits). To complicate matters, there are indigenous alien creatures called Akrid, many of which are huge, who live on the natural energy resources.
A young VS pilot named Wayne is the central character, who wakes up with amnesia after a run-in with a particularly powerful Akrid that also ended up killing his father. Wayne must wade through the NEVEC/pirate conflict, and the Akrid, to rediscover the mystery of his past.
There are a number of games with "mechs" that generally have a very specific type of gameplay. The decision was made early on that, at least for the initial phase of the marketing campaign, the VSs would be severely downplayed, as we didn't want players to get the wrong idea of the type of game this was.
The basic concept of the marketing visual direction was "think of the movie 'Aliens,' set in the snow." This was partly because of the alien world and the tattered, utilitarian technology being used, but also because of the focus on the Akrid as the primary adversaries.