Leap Frog My First Leap Pad: Bob the Builder Saves the Hedgehogs Help Bob save the porcupines as you learn story comprehension; letter sounds; rhyming; vocabulary, numbers and safety tips. Beginning Sounds, Letter Sounds, Rhyming, Characters & Events Setting, Character Emotions, Opposites, Position Words, Math, Logic Skills, Safety Works only on My First LeapPad. NOT compatible with any other LeapPad System. Not Compatibile with the Leappad Explorer