As a Unity dev of 6 years, playerPreffs (the unity system that stores data in the registry) are a good place to store small amounts of data in a dictionary style structure quickly without creating your own data system. But they are extremely limited in the types of data they can hold and the control a dev has over them. Whenever I see playerPreffs used I think the dev must-have needed something quick and easy. They may have also created their own registry save system in that case should be an easy fix. (De)Serializing json or even custom binary files in compartmented files in a defined folder like StreamingAssets gives much more flexibility in data types and control. You can see playerPreffs limitations in the documentation below: (https://docs.unity3d.com/ScriptReference/PlayerPrefs.html)