Would there be a way for an entire team to work together and earn an achievement. Like say you can buy 2 extra tank spawns, but both would cost 150 points. Infected players can all put in points towards them and lower the cost, I put in 50 and a tank spawn cost 100 points. Maybe once all 5 tanks are spawned in, the infected would get an achievement. This would trigger the survivors to get an achievement, if they can kill all 5 tanks they would get an achievement. Or perhaps there are other ways a survivor can get a team achievement, if this is even possible.