It's Necromunda meets octaNe. In an UT2K4 Mod.
Seriously. Just look at those screenshots. I mean, when I saw this, I thought, "Now this is the Wastelands of octaNe. But when I saw this, I thought, "Ahh, but these guys look like Goliath gangers from Necromunda. Even the terrain looks like something scratch-built for it!"
Makes me interested in getting Unreal Tournament 2004...
(Thanks to Penny Arcade for the linkage.)