Things to consider:
Text/story:
Short, descriptive, fun, humorous, rhyming, onomatopoeia, simple sentences, clear/eligible text, introduce new words
Characters:
Recognisable, memorable design, likeable/dislikeable, fun, relateable
Themes:
Moral stories, nonsense, family, counting, friendship, life lessons, humour
Visuals:
Colourful, simple, stories told through illustrations