Hello.

Why Costume Quest asks for Admin rights on Windows, when started from a Desktop icon?

Thanks

Solved by running the "Compatibility Administrator" Fix by Microsoft, which is part of the Windows ADK.

I'm leaving instructions too, if anyone's interested:
Run the compatibility administrator and there should be an option to "create new application fix". Choose the launcher exe, fill out the name fields however you like, and in the list of fixes check only "RunAsInvoker". On the window that asks what files are used just hit "auto-generate". Save your fix, then right click it and choose "install". That should do it. You can try running CQ normally to see if it still prompts, but it should not at this point, at least it did not for me.