quiet a few ways to get stuck...
for example collecting the final pieces for the forth crystal in the bottom right area...
forth crystal increases your size. which gets you stuck down there cause the hole then is too small.
at one point in a previous try, the camera got zoomed out in the middle right area, camera jsut zoomed out and got stuck at that view, socamera doesnt follow the ball anymore and you cant see what the ball does off scren there.
fix it up and ill happily play it again since in general it is a nice game :-)