As a Flash designer/developer for web advertising, are there any vital skills I need to investigate to get into Flash game development?

I"m in a similar situation as you are - Flash Platform application developer looking to bust into games. There's a LOT to learn, it's sort of a different thing altogether - but like many problems in Flash, it's been solved a million times. What I recommend is that instead of learning how to build games in Flash, specifically, you should learn how to effectively use one of the many Flash Gaming Frameworks. Take some time and dive into Flixel, for instance - it'll leverage all of your existing skills, and the "game" part of it will start to make more sense as you go. Here's a link to a tutorial I found to be incredibly helpful: http://www.creativeapplications.net/flash/flixel-2-tutorial-flash-tutorials-games/ From what I can tell, Flixel does two major things for you: 1) It circumvents the DisplayList, and instead all graphics are composited using Blitting. But you never have to worry about that - the hard part is abstracted out, so ultimately you kind of just have to learn the Flixel DisplayList. Blitting is super powerful, basically instead of adding objects to stage you get one big Bitmap added to stage and every frame updates that bitmap. 2) It abstracts out the Game Loop. Every object updates every time it goes through - sort of a built-in Event.ENTER_FRAME handler that's cemented into the very foundation of the framework, and everything extends it. Easy to logically divide up behavior. Have fun, and please by all means post what you make! :)