It’s cheesy.  The characters have kid bodies and giant baseballs for heads.  They’re each named after a different kind of ball (Sammy Softball, Connie Curveball, etc.), and each character’s personality traits/powers resemble the term they’re named after (e.g. the Foul Ball gang are the bullies).  The kids who are old enough to know enough about baseball to appreciate the sport references are going to think the illustrations are babyish and the story rather lame, and the kids young enough to enjoy the illustrations and the predictable plot are not going to get the baseball terms.