(Note: Some of the screenshots used here are also used on an MMOsite review for this game. The reason I don't attribute or source the images are because I'm the one that made them, hence why the images here don't have the MMOsite watermark. Net and myself are the same person.)
Of course, the background story isn't really necessary as no one cares. You are a member of an elite special forces team and your objective ranges everything from eliminating enemies to stopping alien infestations. To simplify, you have a gun! Shoot things! However, there's more here than meets the eye; the developers did a good job of conveying how little they care about "logic". From the whimsical Shatter mode to the recently-added Snowball Fight mode, you probably won't get bored here.
I should also mention that if you played Soldier Front 1 and/or have a personal vendetta against Aeria, try to hold your disgust until at least the end of the review. Now then, let's get down to the nitty-gritty...