Very nice physics! Seems a little too bouncy against the bottom edges sometimes, when the balls seem to be traveling quite slowly beforehand. You could extend it to have some surfaces that are very bouncy (like the obstacles in the middle of a pinball game) and some which are less so (solid objects, as some areas of the boundary might be) - but that really depends on the nature of the game (I'm not a big pinballer myself...)

I really like the menu you've done on this! And the pumpkins are good too! (Can't quite see what the combat greeps are doing yet though...)

I like the bomb explosions! It took me a while to get used to how the controls work though - maybe you should remove the old instructions from the description? Also, at the moment the enemy missiles just slide across the top when they get there - a simple if(getY()==0){getWorld().removeObject(this)} in the end of the missiles' act method should be enough to let them appear to leave the top of the screen. But then I do quite like the fact they do turn round & follow you again...

Cool! I like the visualisation of the pressure & the way the sand reacts to it - although sometimes the sand does seem to act a bit strangely.

Could do with better gravity (and possibly the ability to jump off the top of the screen, or fall back down through platforms, otherwise I find level 4 very difficult). Good start though, and brilliant scream. One other ting: when you press a number button to skip to a level it makes a strange sound. It might be the applause being played a few times at once?