Overview
A guide to secret achievements (those without a description).
Introduction
All achievements aren’t discovered by me, I found out about them in this discussion. So, I (and you) must thank these guys, not me. Write “+rep” in some of their profiles.
Ballooning
This one is very simple, in main menu you must click on the balloon silhouettes, they look like the one in the image of the achievement. Click on them till you get the achievement.
This is a screenshot, where you can see where you should click.
First stated by tingeltangeltom
Well, after some update the background changed, and the achievement was unobtainable (my guess is that the devs messed up), but it’s fixed now, and baloons are there once again. The way you obtain the achievement didn’t change (just click on silhouettes until the achievement pops up).
Special thanks to Mitula for pointing out that the achievement doesn’t work anymore and to strider_9000 for pointing out that the achievement is now fixed.
Beyond the gate
This one has a description, but you may think:”How can I do that?”. For this achievement you will need 3 metal cubes (like the one in the image of the achievement) and to use them to make your portal adventures longer.
First stated by tingeltangeltom
Also, as told by Persona non grata, if you use a tome page of unholy travels in the portal dimension, and be teleported into the corrupted world, and getting a bloody crown will return you back to the portal world, but there will be no time limit. I think it’s a bug, because the image of the achievement IS a metal cube, but this method also works (at least it did in 25/08/18)
Schroedingers Box
You have to wait until you got a harbour mission where you should find a mysterious box. You will get a treasure map with its location. Find it and dig for it. You will need a shovel. If you open the box you will get the achievement. And the map will start to be consumed by the void but eh, who cares about that when there’s an ACHIEVEMENT on the line
First stated by tingeltangeltom
What lies beneath
For this achievement you must blow up a mountain face (and, of course, like the one you see in the image of the achievement) and find a hidden temple under it. You need a dynamite to blow it up. Not every mountain face has a temple beneath, so you must look for it a little bit. Here are the screenshots by dconnor:
First stated by dconnor
Secret session
For this achievement you must beat the game with werewolf (custom character, you must type 1941 in settings)(don’t know if other custom chars do the trick). I don’t know if you can achieve it on easy difficulty or not.
First stated by F😈CK HOPE, but was bugged, then verified by Grawp
Hungry Heart
For Hungry Heart you need to wait until you have a harbour quest to find a lost explorer, then, you must cure the lost explorer from cannibalism before bringing him in London. Shaman hut and green shrooms do the trick.
First stated by Lentobombe
Cold companion
For this achievement you need to find Yeti in the arctic and tame it. In order to do that you need to find it in the arctic (it’s a rare encounter, found in caves). You will have 3 options: attack (starts a battle), do nothing (starts a battle as well) and give it an item (you now may tame it). In order to do that you either need to give it 4 items it “likes” (the wiki page says that whiskey works, unsure about other items) or improvise by rolling a combination of 
and 
I should mention that if you do kill it you’ll get 2 yeti paws, which are necessary for the “find every item” achievement.
Also, it’s considered human in the party, so you can rank yeti up be normal means
First stated by Lentobombe
Special thanks to the yeti wiki page[curious-expedition.fandom.com] for providing additional info
Corrupted king
For this achievement you need to find a shrine where your char will say that he sees fungal growth. After you loot the shrine 3 or 4 spider caves will appear on the map. You have to get into them and fight the spiders and there is a chance that an option to “enter the clearing” will appear. Then you will be teleported into a corrupted world and there you must find an Unholy Altar, and there you will find a Blood Crown, and will be teleported into the real world.
First stated by Lentobombe, then verified by Savil.
NinjaFrog found out that using a tome page of unholy travels will teleport you into this corrupted dimension too, where you can find this crown.
Made for battle
For this achievement you need to buy a battle tiger from beast master for 15 teeth. Battle tiger can be found in every region.
Found by myself, but first stated by Lentobombe.
A tribute to Yama
For this achievement you have to sacrifice a Golden Eggplant at a Sacred Pool where you can resurrect your dead party members.
Solution found by Mustardoish, but was bugged, then verified by Grawp
Pattern Recognition
For this achievement you must find a place on the map, which is at the center of a triangle formed by three special tiles (don’t know if it has to be stones or it can be other objects). The special tiles will be exactly 5 tiles to the bottom, 5 tiles to the upper-left and 5 tiles to the upper-right. Dig at that spot using a shovel, get a treasure (nothing special) and the achievement. Screenshot for reference by Savil 
First stated by Savil
Unchained
Unchained is quite a straightforward achievement – all you’ve got to do is defeat slave traders (which possess a neat weapon which you also can get – the whip), which can be quite tough for a non-hunting party, but are otherwise easily beaten (make sure to have med kits), and free the slaves (which massively boosts relationship with locals).
