"A small number of PS3 Prototype owners have been having issues with installing the game," Prototype development team admitted on Activision's official site. "This is a known issue and there will be a patch released on PSN shortly (details to follow)."
"If your PS3 tells you that you have insufficient hard drive space to install, even if you do, you are going to need to change the available space on your hard drive by 700 MB. This can be done in a number of ways including the following:
- Installing or uninstalling another PS3 game that allows hard drive installation.
- Downloading game demos.
- Removing downloadable content.
- Adding / removing MP3's or movies from the hard drive.
- Etc.
Once you have made the necessary change to your Hard Drive space insert the Prototype disc back into your PS3 and it should now install.
The goal of this is to change the available space on the hard drive. You may need to try a combination of any of the above suggestions."
Prototype development are working hard to fix the issue, and a patch will be released soon.