The latest release of Motor2 is using the Vectors class which means you have to compile your files for Flash player 10. If you for some reason don’t want to change to FP10, Michael (developer of Motor2) has the solution:

replace all Vector occurrences with Arrays
http://groups.google.com/group/motor2/browse_thread/thread/182291562d7dfd9a

Motor2 version 0.9 is released and can be downloaded here:
http://code.google.com/p/motor2/downloads/list

Take a look at the changelog:
http://code.google.com/p/motor2/wiki/Changelog

I have been working on a skateboard game at work using the Motor2 physics engine. I am looking forward to the feature where you can change the groupIndex (used for collisions) runtime to be able to use the rails I have set up in the world. Michael who develops the Motor2 engine says he will soon release a new version. Really great. Eventually I´ll share some code and screenshots from the game.

The Motor2 AS3 physics engine makes it really simple to create platform games. I have made a prototype game that only use BoxData and LineData (used for the jump through platform). There is really no functionality except walking and jumping, but then again it is a prototype.

The wall-jump bug is a feature! Or … the wall-jump feature is a bug.

UPDATE: Use the arrow keys to move Mario.

I have been playing with a AS3 platform game and wondered how to make jump-through-platforms like the ones in Super Mario Bros. I found out that you can create a LineData body and set doubleSided to false. This allows you to jump through the platform on your way up.

// a, b, infinite, doubleSided
var lineData : LineData = new LineData(
    new Point(0,0),
    new Point(100,0),
    false,
    false
);

I have been playing around with the Motor2 physics engine which is based on the Box2d engine. I really like this engine and think it has a lot of potential for actionscript game developers. Box2D has great documentation while Motor2 does not have any documentation at all. My advise when you start to work with the Motor2 engine is to have the class files rather than the swc files in the project. This will help you get a look into the code to check the parameters and methods.

Google Code
http://code.google.com/p/motor2/

Google Groups
http://groups.google.com/group/motor2

Box2D Documentation (may help)
http://www.box2d.org/manual.html