Crystal Heart
Crystal Hearts are high-importance collectibles in Celeste. Their primary purpose is to unlock different chapters locked by Crystal Heart Gates; they are also a prerequisite to unlocking all C-Sides. They also serve as chapte completion objectives for all B-Sides, all C-Sides, and Core A-Side. Blue Crystal Hearts appear in every A-Side; Red Crystal Hearts in every B-Side; Gold Crystal Hearts in every C-Side, and a Gray Crystal Heart in Farewell. Each Crystal Heart, minus C-Side ones, also has a name specific to itself, and an associated achievement with the same name.