I've tried to play gamecube games on dolphin and it never worked. For project 64 all you do is extract the folder and run the program.
But for dolphin it always had some error, like you have to add different files to the main folder, I don't understand why..?
Mainly because they use a lot of grafic apis. So you need to find the dlls to make it work. Dolphin is in active development so its going to be that way. They have all that info on their page.add different files to the main folder, I don't understand why