I sell those in my store. There are loads of other cards you can get for it. They go by habitat, ie swamp, forest, birds of the south. There is a 4 card set just on warblers. A frog card (makes everyone laugh!)
It has a volume control and an ear plug so you can listen to the machine and a bird to try to match them up. They're fun for quizzing each other too.
I sell loads of them.
My demo machine is going on 6 years old,with customers playing with it, and still going strong.
A nearby
plant nursery had a lecture on bird gardening and birds,used it in their demo, and a bunch of the people from the lecture came to get one and more cards.
I'd say if an 8 year old wants a machine that interests her in birds and nature instead of a video game...Go For It!