The main draw back is that the first version of Hack & Slash is quite dated (uses Unity 3). However the author has started creating new tutorials with Unity5, including a new Hack & Slash series in the works.
Unity Learn provides a variety of ways to learn about tutorials. Projects provides step-by-step tutorials on creating different games. There are tutorials on a variety of different topics, such as audio and navigation. There is also the official documentation and community.
These tutorials are less than ideal for beginners who don't have a programming background. Though Unity Learn does provide some coding tutorials, they tend to be faster paced than is comfortable for someone learning their first programming language.