Thanks for the comments, really appreciated!
My play on the theme was that you can only go back (rewind) to a previous chicken form so once you transformed, you couldn't use the previous form, making the player think in advance what they had to do in order to not get stuck in the puzzle. From what you're saying and other comments, I see now that I should have made that more clear.
The question marks where only a way of telling you, the player, what type of form do you want to go after the egg? There's nothing, you can't :D (but, from the first point, that wasn't clear ^^' )