Detail this asset from Unity Asset Store: Original Link
This is a paid asset, but now you can download Mini-Games from Space! Free.
Mini-Games from Space v1.0
A simple game that revives the feel of the old handheld games.
You can choose what game you want to play: killing enemies in Space War, or rescuing astronauts in Space Rescue.
This is a complete game with fully commented scripts in C#.
In this game you can see how to:
* Use the new UI from version 4.6
* Work with global data through Persistent Singletons
* Use object pooling to prevent performance loss.
and the basics of 2D games:
* Sprite movements
* Play sounds
And use only one scene to show all the game screens.
A small description of each part of the game is presented in a PDF document.
For this tutorial you need a basic knowledge of C# and the Unity version 4.6.