When World of Goo is run in windowed mode on Mac, 10.5.5, the mouse location does not line up with the cursor when moving quickly across the screen. This is a problem for Chapter 1 Level 3 where goo balls need to be thrown. The cursor will appear within the game window, but the actual cursor will exit the window as you drag.

Maybe locking the cursor within the game window whenever there is a mouse button is pressed would work.

Playing in full screen works fine, but I'd rather play in windowed mode.