Save level

Example

This is an Editor Script.

Exists same script, but MonoBehaviour?

What is PlayerPrefs.Save

First of all, you'll need some way to access all the data you need to save.

If you create a GameData class and put every variable inside this one, it might be a little easier to use.

Secondly you need to program 2 functions, as you mention, a LoadGame() and a SaveGame()

These two functions will then either:

Grab data from PlayerPrefs and store it inside the GameData variables. or Grab data from the GameData variables and store them in PlayerPrefs.

PlayerPrefs

http://unity3d.com/support/documentation/ScriptReference/PlayerPrefs.html

You have to use these functions to GET or SET the values from your code.

Whats in your GameData class, I dont know as you havent shown us any code.

(note: I find your question rather general and with too little details, but I have tried to provide something usefull anyhow)