Congrats!!
Some time ago I've seen a game on Greenlight which was exactly like Swordlord but with fancy 3D Unity or Unreal graphics. I had thought you had switched engines and remade the game but apparently... YOU didn't.
Instead someone seems to have seen your game on greenlight (or somewhere else, itchio?) and just copied it, which is a shame. :< Can't find it right now but I will link it here when I do so.



EDIT: @Kartoffel: I was so bummed and stumped when I first had a look at the Steam API, especially because I didn't know any C++ - and I still barely do.
A good start is to read the DLL stuff in the manual and have a look at the content of the "sdk_" folders in your Gamestudio installation folder.
You can already have a look at the Steamworks SDK too, even if your game is not on Steam yet.