There were times we had to do numerous reloads trying to work our way past some guards. Usually you play co-op to make a game easier, but segments that require stealth (and cause failure on alarms) can be quite frustrating. I found it a bit odd actually, it felt more difficult. Now that all the technical stuff is over with, how does the co-op actually play?

The only time someone can join is before a mission begins. The game originally touted drop-in/drop-out play, but that's not supported. You aren't limited by mission progression for joining a game, but your progress won't carry back to your saved game other than any unlocks you may have earned by completing bonus goals. Despite having an open option there isn't exactly a way to FIND public games. What's bizarre is you can set a match to be private, friends only or open. You can join any match, provided you can find one.

The entire campaign in Future Soldier is playable in co-op, though you'll need to bring your own friends because there's absolutely no form of matchmaking whatsoever.

Ghost recon co op campaign