My daughter has enjoyed this cardboard block set. She enjoys the blocks because they stack tall, unlike her smaller plastic building blocks, which do not stand well on the carpeting. She often builds up the blocks, knocks them over, and starts over again.
She does not care about the pictures on the blocks, but she recognizes the letters, which are all written uppercase. Some of the blocks are difficult for a toddler to associate the picture with the letter (e.g. a rabbit with a rose for the letter "R," but most toddlers would see a bunny with a flower).
I have used the blocks for other games, such as "Memory" by hiding smaller objects (such a sock or paper) under the blocks and asking her to remember which object is under which block.
I would recommend this product for children aged two-years and older. The cardboard blocks could easily be damaged by a younger child, rendering the blocks unstackable.