I'm a big fan of under-represented games, as nearly 2500 points of Battlefleet Gothic, Inquisitor rulebooks and Mordheim warband suggest. It's only by virtue of my FLGS not stocking them that I don't have a horde of Battlemechs and Heavy Gear figures in my cupboard. So when I was given the chance to try Urban Mammoth's small-scale sci-fi game Urban War, I leapt at the chance.
And I found a real gem there. Long story short, it's a very fast paced skirmish game with a healthy variety of factions to try out and some nice minis. While nothing is going to topple GW's domination of the market for light, fantastical wargames, UW is a nice alternative. The aesthetic is a bit more video-game or anime themed than 40k, but I don't feel you lose too much from the lack of Grimdark. I'll begin with a rundown of the faction aesthetics and play style (the fluff is interesting, but I personally wouldn't say it sells the system) to whet your appetites, then move into a discussion of the rules.