Complex subjects aren't always covered to their full depth. Due to the short length of the videos and some topics that might not be as familiar to Sal Khan, the only presenter on the site, some concepts and ideas get just surface coverage.
Scripting is not the first topic presented in the Unity tutorial series, and it is assumed that you are already familiar with Unity's basic operation. For those who are just starting out, this could mean some extra study before getting into programming.
Scratch teaches core concepts and techniques which are essential to any language, and uses a block-based visual scripting system which strongly resembles the format of mainstream languages, but is not directly based on any language in particular. Learning another language is still required to use...
Visually-constructed code is translated to the Haxe language and can be inspected as text. Direct Haxe code entry is also supported, but other than a single appendix on the "Code Mode" this is not covered in the Stencylpedia tutorial.
Explains the complete process of making a cross-platform game written in C++ and using SDL. The tutorial starts from the beginning by setting up the environment and goes through the motions to eventually create a cross-platform game.