The Lost Mythologies

For this achievement you have to download DepotDownloader. To download the right Depot to make DepotDownloader work you also got to download DotNet SDK

DepotDownloader: https://github.com/SteamRE/DepotDownloader
Dotnet: https://dotnet.microsoft.com/download

After having downloaded DepotDownloader and installing DotNet you got to edit the "depotdownloader.bat" file and paste the following:

@echo off
cls
set /p user="Steam username: "
set /p pass="Steam password: "
cls
dotnet DepotDownloader.dll -app 372540 -depot 372541 -manifest 4673839935112621836 -username "%user%" -password "%pass%"
pause

after that run the file write your username and password and if you got the authenticator on you got to fill that in aswell.
When done correctly you'll see in the depots map the depot where you have to copy all the files from and paste it in the directory of the game normally the path should be like this:

C:\Program Files (x86)\Steam\steamapps\common\The Lost Mythologies

if you want to be safe you first back up the files before pasting the depot files but normally it's fine to write the files over.