sorry for not immediately reply (I hope is not too late)
1. if you mean the title screen puzzle,I think let red eat every fruit will do.
2.for level Y you need to use the extra ground to let the yellow move again. and I won't tell you when to eat what.
you probably already done level X so I believe you can figured out.
3.for level X you need to find two different way to push the yellow up once, and reaching that part is the hard and fun part.
also solve all 4 star level to scroll the credit screen

I did it.100%completed. a lot of them are hard,but i'm happy is done. 10/10