(Solved) [Steam] 100% Completion achievement not working

[geekahedron]

I have been playing on Steam since its release, and converted/updated my walkthrough and flowcharts for the new version, including adding save points for the "Bundle of Choices" achievement, since there are a decent number of dialog options that only appear in certain circumstances. After all of that, and completing the game multiple times, my library shows 100%, the gallery is as complete as it can be without the patch, but I still have not been awarded the 100% completion achievement on Steam.

missing.png (551.46 KiB) Viewed 673 times

It's the only achievement I'm missing, and I would like to think I know the game well enough to confidently say I have seen and done everything, so it must be a glitch, but has anyone else experienced the same? Or anyone on the development side that could look at a save file and determine if I have in fact missed anything?

[geekahedron]

Okay, never mind! I have been going crazy, but someone finally gave me the answer in the Steam community discussions. All of the achievements are triggered during gameplay except the one for 100% completion. To get that achievement, you must view the final "Thanks for playing!" image in the gallery. I've added that note to my guides on Steam, and I'll leave this here to hopefully save other people from the same headache.