Make sure you've selected the "Open City" option when selecting which New Mombasa level to play. Find every audio log, then play every level while still in the Open City.Awesome info. Ok so we have already found ALL 29 audio logs. So from here, either single or co-op, we need to restart the Mombasa Streets - Open City rally point 7 level from the beginning of that map?, all the way until Data Hive which is rally point 8 after Open City rally point 7 is the next presented Map level? Or start at the Recon Helmet rally point 1 level? And progress from there? We see 8 maps under Mombasa Streets. Open City is RP7 and Data Hive is RP8. Can we start at Open City RP7 and go from there?
I repeat, do not exit out of the Open City and play each mission from the main menu, that does not work!Progress through each mission in Open City(you'll notice they are all available from the start, so it doesn't matter which order you play them) until Data Hive becomes available. Play this, and that dude you meet in the level won't die, and the final audio log will be accessible. A bit later, the dude will say something like "stay here, I have to check something," but follow him anyway, wait till he starts trying to kill you, kill him, then listen to the audio log, and the achievement should pop.
If you're doing this co-op, it would be preferable to do it in one run. The second player's progress wouldn't be saved if he quits the game at any time, since he is not the host.
I hope this helps!
Just getting the details of what we need to start since we've tried a few different things. The only other items we have NOT found is all the Clues. I have 3 of 6 and missing 2, 3 and 5th Clue. Does the Open City Mombasa levels have these clues.
Thanks for you help and info. What I was looking for. Any chance you open to Co-Op on ODST?
Use exclusively Open City, it's pretty much the entire city of new Mombasa without the restrictions the other rally points put up. For instance, the Recon Helmet RP only lets you travel the path through the city that gets you from your drop pod to the helmet, while the Open City RP lets you travel to all the "clues" I believe you're referring to, including the helmet.
This means that all of the clues are
in Open City, and their locations are clearly marked on the city map you can access by pressing the button directly to the left of the Home button(I believe it is called the "menu" button....?).
Unfortunately, I don't believe finding the audio logs in a separate RP next to Open City counts toward the 30th log. If cars are honking their horns and blinking their headlights, or the Superintendent is repeating a line of dialogue infinitely, it means an audio log you have not found is nearby. These signs are proof that your previously collected audio logs don't register in the new save. You'll have to find them all again, together, in one run, if you both want the achievement.
You'll never need to use any other RP other than Open City, all the campaign's content is accessible from there. If you just load up Open City, collect all the audio logs and progress through the campaign like normal without ever quitting to the main menu on co-op, you will both get the achievement. It's a lot more forgiving on solo, since you can save and later resume your progress mid-mission.
I'm afraid I do not get on much on evenings due to my roommate automatically reserving that time for his battle to complete Dark Souls III, so I can say I'm not open for co-op at legitimate times. I'm sure you could make it on your own, though :)