Here is one of the very early prototypes of Jacbil Gobbet:
http://www.stencyl.com/game/play/35207Use arrow keys to move and Enter to dig.
Jacbil is made with the image API. All "physics" are image API based. The squares at the bottom of the actor represent the locations of "get pixel x,y in image" that determine whether a pixel is colored or blank. Pressing enter uses the mask Stencyl block in the image API to dig. Since masking eliminates pixels from an image, the actor then falls as if a hole was made in the ground.
About me: I have Ph.D. in environmental microbiology and genetics. I was a microbiology professor before becoming a game developer 3 years ago. I spent a few years looking into game development and Stencyl before deciding to switch. Even though I thought I knew what I was getting into, I knew nothing. I had zero education or experience in game development before. Even now, I keep realizing that there is so much more to learn and so many new techniques to figure out.
Best practices: come up with simple projects that you can get done in less than a month. If you spend longer than one month, you will probably never finish. Once you have a bunch of small games under your belt, you will have the confidence and experience to begin thinking about larger projects.
Valuable tutorials/guides: I have no idea. I have not used tutorials. My guide has been playing around. I use the "draw" blocks constantly. When I first start on a new prototype, the entire screen is filled with drawn text. I draw x-values, speeds, calculations, booleans, lists, and anything else I might need. I keep playing around with block configurations until something works. I learn best by doing. I am not book smart. I get nothing out of sitting through a lecture or watching a tutorial. I play until something clicks and then I can remember the method I used for figuring it out the next time I try it. Normally, playing also allows me to discover out better ways of accomplishing something that I tried to figure out before.
Good materials: I make my own stuff or hire out work to designers/artists/musicians. I would recommend against using assets from open sources because you never know if they are stolen. I also only recommend using someone else's code if you need a reference point for learning a new mechanic. I still think people should play around with creating their own style of coding rather than copy/pasting someone else's code. If you want to hire someone to code something for you, that is fine. But most people's errors they seem to have in games (just check out the Ask a Question forum) come from using other people's code.
Work after Stencyl: I have been a full time game developer for almost 3 years. Quite a few people are making a living on Stencyl (check out Colin Lane as a great example). There are no rules saying that there needs to be an "after" Stencyl. That being said, you can learn computer logic and even haxe coding (you can use view code commands) with Stencyl. Learning computer logic alone would be most applicable to other visual engines - such as UE node-based blueprints. Learning the haxe coding behind the Stencyl blocks would be applicable for understanding any object oriented computer language. You would just need to learn the new syntax.
Best of luck to all of you!
Chuck