There are a lot of textbooks for mechanics - why another one?
Because reading this textbook should be fun - but as a side effect the reader should also learn the basics of mechanics without suffering to much! Or to say it more officially: The scope of the textbook is to teach mechanics by means of simple examples from everyday life instead of sophisticated scientific approaches. The examples, supported by a lot of cartoons, should help to learn by associations and practical experiences. A similar textbook has not existed before - the terms "mechanics" and "fun" have always been contradictious.
A strange textbook - is it possible to trust in the authors?
You can trust in the scientific education of the authors. They have taught mechanics for about 10 years at the University of Hanover, Germany and know about the problems involved when students collide with mechanics. However - you should not trust in the authors with respect to their obligation to extraordinary scientific approaches - the authors rigorously eliminate theoretical blow ups. But the authors would be prepared to defuse the humour in some cases if necessary ...