Whereas planet 1 focused on short-vowel sounds only within words that followed a consonant-vowel-consonant pattern, planet 2 moves on to more complex consonant blends (where you hear separate sounds for each consonant) and digraphs (where the consonants work together to make one new sound).

Level 2-1 focuses on three consonant digraphs: the ch, sh, and th sounds. For simplicity, in this level the digraph is at the beginning of each word.