Hi! I'm stuck at the mine level, at the maze with the three levers. I pulled down all three, but the gate didn't unlock. What am I doing wrong?

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Anyone have hints on these achievements? Is there something you have to do in the forest level before going in the mine? Or can these be done by doing specific actions in the mine level without doing anything in the forest?

Does anybody know how to reach "Secret stone" achievement? I have tried everything I could... I have found a place of the Stone, but what things do I have to do to reach that achievement?

Maybe there is something I couldn't find out yet, but I believe that I have found the place of "Secret stone" achievement already (judging by the picture on Steam and the place I've described). But when I tried to click on it, there was only "massive wall" subtitle and the game didn't . Does anybody know how this achievement works? I have been trying to find it out, but I am still not successfull. So, I would like to know, if I have to find something like a secret object to interact with the "se...