WWW.LoadUnityWeb vs. PlayerPrefs

The WWW.LoadUnityWeb documentation suggests that PlayerPrefs be used to pass information between the current and new .unity3d, however since each URL has its own PlayerPrefs, I can’t see how that helps (unless the .unity3d is loading itself, which would be pointless).

My specific purpose is to load an older version of the game if the user’s save game (found in PlayerPrefs after loading) is not compatible with the latest version, so I can’t use AssetBundles.

No, not every URL has it’s own PlayerPref file but each “product” have it’s own. It is of course sorted by the domain name of the url but the actual URL doesn’t matter. You can split your game into multiple seperate levels and each level goes into it’s own unity3d file. It’s almost like asset bundles but it also works with the indy version. You can only load a complete new file, you can’t load just some assets. As long as all files belongs to the same product you can access the same playerprefs.

Of course you can’t access any data, preferences or anything else from other domains, that’s how it always has been in the web world for security reasons.