I played the first Zoo Tycoon and found that ZT, along with RollerCoaster Tycoon, are the only two Tycoon games I ever really fell in love with. ZT2, unlike its predecessor, lets you play with your animals in 3D, even letting you teach certain species tricks and allowing you to walk around your own zoo in Guest Mode (something I liked in Sim Theme Park). I like being able to see the faces of my guests, and one guest even turned to face me RPG-style and stared when I was staring at her, which I found pretty cool. I was skeptical of the graphics at first since they didn't seem to be a style I would like, but for a 2004 game, they're really not bad at all. Your selection of buildings and objects isn't great, even with the expansions, but there is enough to work with to keep the game going; the main focus is instead on the animals and their food and toys.
There are a few annoyances; for example, some things get auto-placed (like some statues) without notifying you and end up blocking off areas (which you often won't notice until there's a complaint), and you're only able to build things after you've manually removed the trees and rocks that are in the way. Your selection of buildings and scenery is very limited, and since one of my favorite parts of the Tycoon series is the interaction with guests, this is a downer. The game also doesn't seem to be extremely thoroughly tested since the tutorials got stuck for me once and your zookeepers do relatively little, which ends up making you pick up after the animals yourself for the most part. All in all, though, I was impressed by how fun and engaging this game is, and how long I played it in my first few sittings.