I've downloaded twice and both are a pkg file and not the usual executable installer of a gog game. What am I doing wrong?

I believe pkg-files are for Mac (and sh-files for Linux). You have to change the system in the system-tab (? not sure about the english word) (since it seems to say Mac for you). If it already says Windows/Linux, try changing it to a different one and back to your system. If it's still the wrong file-ending, the wrong installer might have been uploaded for the system. In that case, you would probably have to contact support to get that fixed.

That fixed it. This is the first time I had this, I have idea how it switched to mac. But thank you again very much for the help.

You're welcome. :-) (Happens to me sometimes too and I don't know why either.)

Oh, man, I was confused at first after downloading that file. Thanks for the help. It had never happened to me before.