http://goofans.com/world-of-goo/easter-eggs

but that's not all of them

4, 5 ,and 6 don’t exist.

5-roll the ball off the other end

Oh I forgot about that one. But what about 4 and 6? And also , 1 is not an Easter egg unless it’s not the one I think you’re talking about.

I'm not sure how the first one is an Easter egg.

The 2nd one isn't an Easter egg. To quote:

By the 4th one, I'm not entirely sure what you mean. I guess the sign that's kind of hidden could count.

the 3rd, 5th, and 6th ones do count though.

There was also the IOS Easter eggs, including the mighty blimp.

The window texture square also has a texture resembling its ball.xml code, although I'm not too sure that counts.

MOM's computer has a sign in the very upper right corner (about twice as far up as the MOM shortcut. same on weather vane. Ivy towers: C+J (I think)

I heard there were 12

He could be talking about the unused bird images in the Weather Vane levels folder

there is a difference between an easter egg and an unused image (or images in this case)

there is a difference between an easter egg and an unused image (or images in this case)

Actually I guess a sign doesn't count as an easter egg so Weather Vane and Mom's computer don't count (by the way I had no idea there was a sign in the upper right corner of weather vane and that's what i meant by easter egg).