Whereas the original Lost Planet was set predominantly in the snow, its sequel features more varied environments, including tropical jungle and a run-down city. To aid co-operative play, Campaign mode is broken down into episodes and chapters and you can jump into any of the chapters you have completed, at any time.
While co-operation is central to Lost Planet 2, at the end of every chapter, each player is given a grade from S to C, depending on the size of their contribution. This provides a good incentive to replay chapters and try to beat your previous score. You'll also earn points which increase your character's level and unlock new weapons and parts with which to customise him.
Similarly, there is a Training mode in which you can earn bronze, silver and gold medals by beating increasingly challenging objectives.