The first page of that tutorial does say that you need a license for the bundle:
[quote:1b6oynrf]This tutorial uses the Jungle Platformer sprites from the bundle you get when you purchase Construct 2. Once purchased, click the Download media bundle link in the About dialog to get the extra assets bundle.
However, any graphics - even if just placeholder shapes - will be adequate, as you will learn valuable knowledge of the mechanics of the system regardless.