If Level 1-1 was about the basics, 1-2 introduces the good old fashioned wall-kick to the game, which is a nifty little technique for shifting Mario backwards for a moment in order to pickup coins – collectable or otherwise.
The temptation in this level is clearly to try and tempt you to grab a few extra gold coins using the wall-kick, and for the most part, the level is structured in a way that makes it both enticing and inviting. Regardless of how you seize the opportunities of this introduction to the wall-kick, it is a handy technique that will come in handy in future levels.