We're big fans of the classic Dobble here regularly and we play there with our 6 year old son 1/2 (for at least 1 year). It's a game he plays with her friend the same age as him, without supervision, independently, proving to me the real success of this play. His little brother 3 years ago regularly asked to play, and at the observation, was doing well; by cons, it was much more difficult in terms of speed, both of enunciation (try therefore, yourself, said drop of water drop of water very quickly and you will see ^^) and recognition of the small card. so we had to play only with the recognition in mind, without the speed (which is much less funny). Here, with this pack, no need to adjust the rules: the circus Dobble Dobble and kids, there are fewer symbols on the cards (6 in total) which greatly simplifies the task of small players. The rules remain as easy to understand and the game still funny to play.
As usual with Asmodee (excellent games publisher), quality is the appointment (I am thinking of the strength of the cards, sometimes abused by an excess of enthusiasm, but that age well!).
Here's a great package to offer a child ... or her parents!