I've downloaded it a few times and every time I try and launch any of them, they say that the files are damaged. Now I am running Mac OS 10.9 and it is a fresh installation of the OS so there isn't anything unusual I could think of that would cause this issue.

All four games do the same thing.

I tried Primordia (also from Wadjet I believe) and it launches fine.

Same thing has happened to me. None of the games will open. Like the previous poster, I am running version 10.9 of the Mac operation system. The older version of the Mac installer ran fine on my machine. I aasume that there is something wrong with the new Mac installer.

READ FIRST (MAC OS X): Common troubleshooting steps

READ FIRST (MAC OS X): FAQ and solutions for known issue

I managed to get it to work by using the GOG Downloader. I guess it downloads a slightly different version.