enableRegionInteractivity option to true.markerOpacity option to 0.5.sizeAxis option to {minSize: 2, maxSize: 30}.magnifyingGlass option to {enable: false}.keepAspectRatio option to false.forceIFrame whose default is true (the current behavior), but can be set to false. When set to false, corechart charts, geo chart, treemap and gauge will not render the chart in a iframe (for all browsers excluding IE<=8). This is still very experimental, and undocumented. We would like you to try it out and give us your input!