So I came across this thread on the Steam Forums and, given the lack of a thread on the issue in this forum, started to pretty much repeat it here. Also, I've tested this and tried to get these achievements myself and noticed that I can't do it either, no matter what I try. 

And if you notice, all of those achievements have one thing in common: they're connected with the way you win (or lose, in one of them) a sea battle, so I guess there's something in the game that isn't registering the outcome of naval battles properly.

Hey there :)

So I tested them with a new steam account and I could unlocked all of them...

=> It Came From The Depths

Attack an army containing only land units with an army containing only submersible units (it doesn't matter if the enemy retreat or loose).

=> Full Deck

Win a battle using an army containing each type of Fomorian warship.

=> The Great Old One

Lose an army against the Sea Monster.

=> Go back to R'lyeh

Defeat the Sea Monster.

About the last one, Mare Nostrum, it's unfortunately a known issue. It's in our bug database and we are currently working on it.

I don't really understand why those achievements don't unlock for you. Could you please recheck your achievement list? (Even if I'm sure you already looked at it several times... )

Cheers~!

Mel

Thankfully, I also took care to make my own saves for such an occasion where I might need to test this, so here are my screenshots with a save file if you want to test it for yourself:

It came from the Depths - I used both an army to force a retreat and then another to actually defeat it. None of them worked.

Subs.zip

Full Deck - I even wondered if maybe I had to use the Yellow Submersible, since I believe it's also of Fomorian design, but nope.

Full Deck.zip

The Great Old One - Lost to the monster.

Go back to R'lyeh - Beat the monster.

Monster.zip

And here's my list of achievements. Also, remember that it's not just me, it's also the people on that Steam thread so it's not like I'm the only one with this issue.

Hope this helps.

And here's my list of achievements. Also, remember that it's not just me, it's also the people on that Steam thread so it's not like I'm the only one with this issue.

Yep that's why I'm trying to find a way to repro the issue. :/

I will recheck with your save files and with a new account. I'll get back to you on that as soon as possible.

Cheers~!

I'm back :)

Bad news... I unlocked all the achievements with your save files and with a new account.

=> It Came From The Depths

=> Full Deck

=> The Great Old One

=> Go back to R'lyeh

It's really (really, really!!) strange.  Could you please reload one of your save file (for example Full Deck), retest it once again, and then send us the output logs and the diagnotics files?

If you need more information about those files: https://www.games2gether.com/endless-legend/forum/115-bug-reports/thread/21671-reporting-an-issue

Thanks again, cheers~!

Mel

Sure thing, here they are:

output_log.txt

Diagnostics.rar

Though I created another topic to mention this, I'll mention it here too:

"It came from the deep" got unlocked for me although I did nothing in that respect.

I attached the savegame file to that thread : https://www.games2gether.com/endless-legend/forum/13-tech-support/thread/21787-achievement-and-negotiations

So, it's been quite a while since the last update. Any news?

By the way. anout this sea monster. It is ok, if i kill him twice (with 6 and 8 "units") in one game?