I think the best way to describe the single player is a mash-up between Gears and Call of Duty. Lots of visual and character similarity to Gears: similar color palate, destruction everywhere, "macho" space marine characters, wonky vehicles. And pretty much a carbon copy of Call of Duty game design: linear progression, cool scripted events, engaging atmosphere, chaos everywhere, occasional infinitely respawning enemies, useless friendly AI (all progression depends on you only), etc.
I'm not very far yet though so things could change.