As the other reviewers noted, this is a sturdy set. I purchased it a while back for my baby, who shall be two in late December. This isn't her favorite set (Winnie the Pooh still holds that record), but she does enjoy the animals, and she absolutely adores the car (definitely the favorite item in the set). She's still not much of a builder, but when I (or my husband) take the initiative and start taking out pieces to build things, she quickly toddles over to imitate to the best of her abilities. She sometimes has difficulties assembling the legos, but at her age, it is to be expected. Still, the bright colors of the legos (and enthusiasm from the family) keep her trying until she succeeds at "connecting" one-three pieces. She's not building zoos, at present, but considering that these Duplos are significantly smaller than the Megablox set that she has become quite proficient with, I'm pleased that she's getting challenged. An added bonus is that her big sister (7), who was NEVER into building toys, has finally determined that building with legos can be just as fun as playing barbies, doing science experiments, or reading, etc. Now she, too, plays with legos (but those aimed at bigger kids).
Like the other Duplo sets that I have purchased, this is of exceptional durable quality (quality that far exceeds what I have seen/experienced from the Megablox, but that is subjective), and can be easily washed in the top rack of the dishwasher, should it be necessary to clean them. As for the toy's educational value, my little one is learning the names of and sounds that a few animals make (while giggling hysterically), and she's doing basic construction (though she prefers to take apart what others in the family have assembled). She likes to wander off with the animals, so they wind up near her animal puzzles, allowing her to see/notice differences between two dimensional and three dimensional objects, and the Duplo zoo animals are sometimes used by her when she's playing with her blocks, which leads me to think of the figurines and the car in this set as not limited to the world of legos--they are being mixed by her own associations/whims with her other toys. Again though, the winning piece of this set is the car: it gets the most use by far, and she attempts to place her characters from some of the other Duplo sets inside. This (since the seat of the car has lego grooves, and the figurines have their own attachments) allow her to work at fairly intricate fine motor skills. It's easy enough for me to lock a figurine into a car, but for her it takes time and effort, which just goes to show how fascinating the car and its workings are for her. For a little one, and they do tend to be easily distracted, this one object/skill activity really retains her attention: possibly she relates to the car because it is part of her real life, but who knows.
I would certainly buy this set for another child, but I would choose it for a child ABOVE age two, just as the box recommends rather than for one who is 18-20 months old. Still, a great buy with loads of play value: I believe my little one will find this zoo increasingly interesting as her imagination and motor skill abilities flourish. So, I am pleased!