From Unity member xXLostInPlaceXx comes this handy tutorial video for people new to the Lost Planet experience. 

You get a good look at all the options in the demo, how to make the most of the unique aspects of Lost Planet 2, and of course how best to use the weapons and grenades.  The basic focus here is probably best for multiplayer, but the rundown is useful for single-player as well, so check it out, and do not forget to roll!