Hello,
I think the package file is okay, I have just checked it right now, but I am afraid MAC OS has some problem with the packages. On Windows and Unix/Linux they are uncopressed just fine.
If the installation process showed you the welcome document with no error, then the installation went fine most likely. However, you may still need to check the configuration and finalize some steps manually - like checking if .htaccess file is present or turning the global SEO settings on. Please, follow the documentation and FAQs.