I am a huge fan of these types of game simply because anything fun and easy gives me a break from my 5 year old screaming for help!
However.... this game was very difficult for him, he has had his Nintendo DS for ages now and finds that most games for his age group are pretty easy.
Yoshi's Island has poor graphics and very irritating sound! Many of the levels seem repetitive and it is definetly not suited for the younger gamers.
My son got bored with it very quickly as he simply could not progress any further in the game. Certain parts of the game are quite entertaining but others are too difficult, for example, one level contains a mirror view on the top screen which in my opinion is very hard for any child to comprehend.
If I were to purchase this game again I would certainly consider something a little different, especially for a younger gamer!