Stencyl allows the amateur to create games without having to understand Flash or use coding. As a result of this target market it is relatively simple enough to follow the tutorial and get started. That said it is not necessarily easy to master without a basic knowledge or at least aptitude for programming. It is probably most likely to suit hobby enthusiasts or young potential coders and programmers.
Once you have got to grips with the software the potential for what types of games you can devise is only as limited as your imagination, I found that I was able to produce a solid few games that were enjoyable to play, even when repeated. The software has enough to it to execute a good idea. That said it might seem limited or frustrating to those who are familiar with coding and programming already.
As a free piece of software this is a great first step in to game design, and probably as a stepping stone to bigger and better things. For someone young with some technical knowledge and a budding game idea this could be the start of a career or serious hobby in game design.