Filled mostly with children’s rhymes / songs which can be quite hard to follow as they pick vocab that rhymes together nicely and there often isn’t much context.
It was a fun read but I would NOT recommend primarily as a language learning material, I definitely picked up some new words and enjoyed it though.
I strongly recommend against using this book for N4 study, it contains a large number of N3 words.
For example in some sections where I was counting, every 3-5 questions contained an N3 word.
This led to much confusion and if I hadn’t been checking, it would have seriously undermined my confidence. It also prevented me from using the book to test my speed under test conditions.