This function is just to display this help. The extension uses Box2D (http://box2d.org) as an engine and provides an interface between it and the graphics capabilities of SmallBasic. Only shapes that are connected to the physics engine take part in the motion physics, for example you may add normal shapes (e.g. a gun and not connect it to the physics engine). Once a shape is connected to the engine, it is best to only interact with it through the methods provided by the extension. All positions are in the SmallBasic GraphicsWindow pixels and refer to shape centres. Image and text shapes are treated as rectangles, and ellipses as circles; there is also triangle and convex polygon support, but not lines. Images may be treated as circles by setting the property LoadImagesAsCircles to "True". One issue that Box2D has difficulty with is small fast moving objects that can 'tunnel' through other shapes without being deflected (see the SetBullet option). Another problem is shapes of very different size and hence mass, especially large shapes when they are connected together. It may be necessary to modify the density for these (the Anchor options are an attempt to automate this a bit), otherwise the default density of 1 is good. Resist the temptation to connect too many shapes together. It may be possible to improve the stability of some 'difficult' models using the TimestepControl settings, but the defaults look good for most cases. Do not call the physics methods inside SmallBasic event subroutines directly, rather set flags that can be processed in a main game loop. There are sample SmallBasic programs and a Getting Started Guide that comes with the extension dll - this is the best place to start. Report bugs and problems to the SmallBasic forum (http://social.msdn.microsoft.com/Forums/en-US/smallbasic/threads), but first simplify your SmallBasic code to isolate the issue before providing a short 'runnable' code sample.