I have played it, but not for a long while, so take this with a pinch of salt.
The theme really is very, very light on top of what is basically a polyomino placement game. Each animal type behaves exactly the same, ie. there is no difference in gameplay between the foxes, penguins, meerkats etc. They're just animals that fill enclosures. As for adding rollercoasters etc, there isn't any emphasis on these, they're just useful shapes to help fill your board, they don't have any affect on the animals in your zoo.
If you're looking for a game that does feel more like you're building a zoo, then Ark Nova is probably more suited (it covers breeding, in-situ and ex-situ conservation, animal houses etc); New York Zoo is a much more basic tile-laying game with some animal breeding (the animal meeples are very cute though!)
