It keeps the most important configuration and methods, does not include components. And, there is a quit bit different in interactive mode. Slides could be paused while touch-start, etc.
The challenge for me is that I have to make a trade-off between package size and API richness. We will deviation from purpose if it is too large, it will be useless if lack of important APIs, either.(I'm trying to keep it to be smaller that 3kb, it's so hard ... )