GWT mobile cross-platform drawing performance

I have some ideas for some games that I would like to develop for several mobile platforms. Rather than messing with a different language for each platform I would like some unified platform to go as far as possible on each device.

GWT seems like it would fit the bill for me since I'm more experience in Java. Obviously for cross-platform Javascript seems to work 开发者_Go百科on each device, mostly everything on the market being Webkit (with the exception of WP7).

I'm not looking for hardcore 3D performance but rather some decent 2D performance suitable for puzzle games and at most platformers. I could venture to say that I need between 10 and 500 animated sprites on the screen with a static or scrolling background.

Now I'm puzzled by the fact that I don't know which rendering option to choose. I see there are HTML5 Canvas-based implementation, then there's SVG, then there's VML, then (last resort) native.

Which approach/framework would be best to take in order to have good graphics performance and unified (as much as possible) development? I'm looking to support as many of iOS, Android, WP7, WebOS.

PlayN! http://code.google.com/p/playn/

The same Java code can run natively on desktop (including an applet if you really want to; but this is actually really useful for debugging or quick testing!) and Android; or be compiled to JS using Canvas or WebGL, or soon to Flash (for IE versions before IE9, where Canvas is not available).

No VML, so I guess WP7 support will have to wait for WP 7.1 (which will support canvas). Or you might try to use IKVM.NET to turn it to .NET, and possibly Silverlight; or as a last resort write an IKVM.NET/Silverlight-based runtime for PlayN (implementing PlayN's APIs on top of Silverlight ones, using ikvmstub to make them available in the Java world, and finally using ikvmc to turn your Java bytecode to .NET).