
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.
The total package
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
Features
Graphics
Helper classes for animations, tilemaps, text, backdrops, and more with z-sorted render lists for easy depth management.
Collision
Fast and manageable rectangle, pixel, and grid collision system with a plethora of built-in collision options.
Motion
Powerful motion tweening for linear, curved, and path-based movement as well as spritesheet support and image transformation.
Audio
Sound effect support with volume, panning, and fading/crossfading, complete with one-line sound playback.
Particles
Quick and efficient particle effects and emitters allow for beautiful particle systems without slowing things down
Timesteps
Framerate-independent and fixed-framerate timestep support allow you to decide what mode is best for you and your game.
Input
Simple keyboard and mouse input state checking makes setting keys and events incredibly easy, yet powerful.
Built-in Debugging
Handy console for real-time debugging and information tracking. It even allows moving the camera and inspecting entities while playing!

Pros
▶ A low-cost and incredibly powerful and flexible system.
▶ The internet is awash with great Flash creation tutorials, templates and
code examples.
▶ Some amazing third-party tools and game engine extensions available, all
for free!
▶ Proven ‘in the field’ for many years; performance is good.
Cons
▶ It’s Flash! You either love it or hate it.
▶ Complexity—can be rather daunting for beginners.
▶ Support for some platforms is not as straightforward as with other
development kits.
Website:
http://useflashpunk.net/