I bought this for my son's 3rd birthday and didn't actually realise that the Shrek software which is included is actually for children aged 4-7. Anyway, it is very intuitive and my son quickly picked up the touches required to operate the Mobigo. He's not very PC aware, doesn't use a mouse, so this is his first experience with technology.
It doesn't keep him amused for hours on end, maybe 15 minutes at a go, but then I'm not too worried about that as I don't want him glued to it all day. I feel like it's something I can keep up my sleeve to keep him happy if we go out to eat or on a car journey.
He can do the easy level of the Shrek games without too much support. I do like to sit with him as he will get more out of it from an educational point of view, but he is quite happy to sit on his own too.
I'm going to buy the Toy Story game for Christmas, as it's aimed for 3-6 year olds and also he's not particularly into Shrek but does love Buzz and Woody.
I haven't downloaded the extras yet as I read somewhere that they only last until you turn the device off. This may not be true but I will wait for more info before plugging it into my PC.
Overall I would recommend this as a starter handheld gaming device for younger children.