Create games. Easy.
FlashPunk is a free ActionScript 3 library designed for developing 2D Flash games. It provides you with a fast, clean framework to prototype and develop your games in. This means that most of the dirty work is already done, letting you concentrate on the design and testing of your game.
Get FlashPunk! (1.7.2)
Not only is FlashPunk absolutely free, it also contains everything you'll need to make the game you want. From its robust and dead-simple sprite-based graphics handling to its powerful live debugger, you won't need a team of berets and neckbeards to make your game come to life.
If all this just isn't enough and you absolutely require a team of berets and neckbeards, the FlashPunk Developers community is an incredible resource eager to answer any question you can fathom. Oh, and its free as well.