to unlock the bonus campaigns (thunderstorm and fuel for war) you need to beat the game on elite mode. yeah, so that makes the goal for the impossible be "beat the whole damn game three times"
very cool pictures, nice concept and gameplay. it may not be the most clever game I ever played, but it's fun enough to spend a couple of minutes playing it.
This game is waaay too imbalanced. The first missions, when you have almost no upgrade points to spend, are too hard. The last missions, when your main weapons are at least around lvl 15 and kicking some serious ass, are too easy.
adding to what tivar said, I passed straight from chief superintendent to constable for some reason - probably I had already met the requirements, which i never got to read. the problem is that this prevented me from getting achievement #47, which sucks.
apart from that, great game, keep up with the good work.