Ace Combat: Assault Horizon
51 Achievements
74-90h
PS3
Welcome to Mission Co-Op
Cleared 1 level in mission co-op.
6.9%
How to unlock the Welcome to Mission Co-Op achievement in Ace Combat: Assault Horizon - Definitive Guide
Just go to mission-coop in the mutiplayer menu, then either search for a quick/custom mission or host your own and wait for a player or two to join your game, once everyone is ready you can start the game. Complete the mission and you will unlock this achievement. Most of the missions take 10-15 mins to complete each so not long atall.
See Warwolf Squadron.