How to play widgets in ibooks pages without resizing?

If you mean that you want an html widget to play in the space that you placed the widget, that can be done with in IBA 2.2. You simply choose the option "plays on page" in the widget inspector (interaction tab). When the reader taps on the widget, it will play in the space you have allocated for it.

I am struggling with this issue - I upgraded to the latest IBA, but for both options (Plays on page, Plays full screen), the animation widget is playing full screen on iPAD. It does not want to play in the space allocated for it on the page. Anything I can do to troubleshoot this issue? Thanks.

Even for a "plays on page" widget, the reader can still expand it full-page by clicking in the top icon in iBooks for mac or performing a stretch gesture on the iPad. However, if you just tap on the widget, it should stay in place.