Fuuuuuck... So last night I hopped into a Horde match (Casual difficulty) and we were kicking ass. We failed a few times, but we kept bouncing back and making it to the next wave. We started off with a full crew (of five), two dropped out after we failed wave 20 (the first time), and from wave 20 to 40, there were three of us. Me and one other player powered through to wave 45, but the other player quit after we failed it a few times.
I tried like hell to get through the wave alone, but it just wasn't possible. Didn't have the firepower and it just wasn't possible to hold off the overwhelming force of the AI. Man, coming so close to beating it and then ending up having it all (at least three hours) for nothing was such a kick in the teeth.