|Yep, looks like that.|
What I didn't know about was Gruntpocalypse. Yeah. All Grunts, all the time. Sounds easy, but it is in fact quite difficult. I was only playing on normal, and towards the end it got downright gnarly with all of the little beasties flinging plasma grenades, plasma pistol bolts, and fuel rods at me.
Amazingly, I got to the end. I didn't even know there was an end, since the only firefight mode I have played is from ODST, which was unending. I kind of like having a goal, to be honest.