Chinook and Maia have the following Nina Ottosson games and they love them all. My only regret is not getting them all in wood (I do not like the plastic version of the games, they are easier in some respects - my advice, buy the wood ones)
Pyramids ( only come in plastic but are WONDERFUL!)
Dog Twister (plastic)
Dog Finder (plastic)
Dog Turbo (wood)
I tried the dog Turbo, in both the wood and the plastic and it was very easy for both of mine, so I returned them and exchanged them.
My friend has the dog Brick, and it is easy as well.
The next ones I will buy are the dog Fighter (in wood) and the dog Trubble (in wood) for my two. But that will not be for some time.