It's by no means a bad game, but there is a lot that can be improved upon. Maybe earning different amounts of valor points depending on the type killed. Manual attack orders, and definitley -slow down the spawn from the carrier!-
Hard mode is rather dissapointing. Instead of being hard it's frustrating. The AI isn't smarter, it's weapons are just overpowered to deliver one shots to your forces.
Found that having a defensive line consisting of only shotguns and BARs is the most badass sounding defence there is. Pretty effective, too. If it's in the top half of the field.