I bought a few of these Melissa and Doug puzzles for my 2yr old son, and this one is his favorite.
The pieces are easy to hold by the peg, they're not colour coordinated (the colour of the number is not the same as the reveal inside) so he has to think about it, and spin the numbers around to fit.
The only oversight is that the number 3 fits into the number 8 spot, but the number 8 does not fit in the number 3 spot. Which, apparently, can be quite perplexing and infuriating to a 2yr old boy!
That said, he's spent a lot of time gathering up the pieces and placing them all carefully into position before dumping the whole thing out on floor and starting over.
Great product, well made, and a great value.