Originally Posted by Kobius
Beat waves 1-31 in Guerilla co-op last week. Played through waves 31-50 tonight, no achievement for either of us.
Any tips to get this to pop? - Neither of us really get enough time to play all 50 in 1 sitting.
It has to be done on the same map with the same host each time you decide to play again. I played on Shanty Town (on casual) with three other people and got it done within a few hours.