¿reduce the size of each JARs?, what are you talking about?. You don't need to download any jar file, I don't use applets in this proyect. The download time is for the javascript files, not for jar files.
¿Criticizing java?, please, read carefully and test the game. Play for some minutes and after this, make your comments.

Hello, I integrate the physic engine for java Physic2d with javascript library Openlayers for view physic annimations on web browser. You can view at: http://pv2.homelinux.com making click in one menu option (WHAT, HOW, WHEN, WHERE). The annimation is calculated in real time at server and send back to browser. Then Openlayers paint the geometries. You can see the letters moving on the upper side of the page.

Regards:
pv2Admin

Hello, I develop multiuser game that uses google maps as background. You can find at http://pv2.homelinux.com . I use java APIs like Spring, Hibernate, DWR, JAWR, JTS, etc. I use reverse ajax technology to maintain all users on line. Users can walk, talk with other users logged (near), take objects, look at in one direction. I need to test the game with many users connected at a time. The game work only with compatible browser (IExplorer, Mozilla), you don't need any plugin to play.
¿What do you think about this project? 
Regards:
pv2Developer