Howard's Train. You can go up the stairs but you get stuck coming down the stairs. Excellent.

Passive Observer seems to be 10 minutes not 5. Tried 5 twice. At 10 min to the second it triggered.

Thanks for the guide! Working well so far.

Might be the most blunt and far-fetched achievements ever! Good list, never could have figured them out myself.

floydmw: Thanks a lot for your feedback! I might reinstall and give the game another try to collect the majority of the 'cheevos I missed.

Sorry, that wound up being more long-winded than I'd intended.

Anyway, thanks for the guide, I still found it very helpful.

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Completionist: The guide already mentions this, but I just want to reiterate. There's an automatic story segment that plays at the train station in Little Tipworth, specifically at the platform that runs over the train with stairs on either side. It didn't trigger my first time when I used the stairs on the side where the station is and exited on the other side. When I had to reload my game due to the Howard's Train bug mentioned above, it triggered when I approached the platform from the other side (the side with all the luggage, benches, barriers, etc).

For those keeping score, yes I had to reload my game two separate times in Little Tipworth due to bugs, plus a third time when my game crashed there (and only there) for some unknown reason, plus a story cutscene not playing when it was supposed to. This made that section seem far buggier than the rest and a bit frustrating for me since it took twice as long as it should've.

(Continued)

Anyway, your best bet in my opinion is to do two playthroughs of the game, doing most everything the first time except for the following three achievements. On your second playthrough do Radio Enthusiast, which will take you all the way to Little Tipworth. Create a savepoint here by interacting with one of the story orbs. Then do Backtracker from there, following the path shown in the video but making sure not to open Stephen's bunker first or even go near it since that's what seems to cause the glitch. After the achievement pops, quit and reload (instead of walking all the way back), then open and enter Stephen's bunker to get the final Open Ended achievement. Second playthrough should go much faster since you're skipping the majority of the game.

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Last Orders: I didn't have any trouble with this unlocking like CorvusCorax below did, but I thought it was worth mentioning that it's possible to get stuck inside the Seventh Whistler. Don't try to look too closely at the map in the bar, as you can walk to the other side of the table in front of it but you can't get back out. I lost a fair amount of progress due to this.

Backtracker: As others have mentioned, this achievement is straight-up glitched. It wouldn't unlock for me in my first playthrough. First I want to mention that while there's many trails labeled as "Footpaths" in the game, only walking through the five gates listed in the video are required (I say that for anyone that's only reading the guide but not watching the videos like I did at first).

Some notes on certain achievements:

Passive Observer: It unlocked for me right at 10 minutes, not at 5 as stated in the guide.

Howard's Train: When you go upstairs to unlock the achievement, it may be impossible to get back downstairs due to a bug. This might not happen to everyone since no one else here mentioned it, but I know it's happened to many other people including myself. Highly recommended to create a save point just before attempting it (there's one at the train station nearby).

Radio Enthusiast: Best to save this for a second playthrough. It requires you to not interact with anything at all other than doors/gates and the radios. I didn't watch the video beforehand and thought you just had to listen to every radio message while not interacting with anything until it ended.

Another faulty / glitchy achievement: Howard's Train. I've been standing there for 5-10 minutes without it unlocking. Once you leave the room the train stops. Going back and restarting I thought would solve the problem but the 'cheevo remained locked.