Zoo Tycoon is one of those rare games that transcends age barriers - it can be played by six-year olds and thirtysomethings with equal passion. It's spawned several add-on packs and now it's about to get a complete makeover with Zoo Tycoon 2.

Zoo Tycoon 2 revamps the game with an all-new 3D engine. Gone are the blocky cliffs of the old 2D terrain engine. Instead you get smooth hills and troughs, letting you create much more natural enclosures for your animals. The graphics have a bright, cartoony look that should appeal to kids but there's also plenty of detail in the animals. You can zoom right down in visitor mode and walk around your zoo just like one of the crowd. You can even take snapshots with your camera and include them in an album. There are also snapshot-based challenges available within the game. And for the ultimate interaction you can go into zookeeper mode. In this mode you can perform all the tasks of a zookeeper: grooming the animals, restocking their food and water, administering medicine to sick animals and even cleaning up their droppings.

The slick 3D graphics are not the only improvement in Zoo Tycoon 2. The behaviour of the animals has been made more complex, and the interface has been given a major facelift. The previous game relied on plenty of text, which made it difficult for pre-schoolers. Zoo Tycoon 2 takes a more icon-based approach to feedback so that even non-readers can work out what their animals want. There are around 30 animals available and a whole range of buildings, animal shelters and toys and zoo improvements that budding tycoons can equip their zoos with.

Creating the ideal environment for each animal has also been simplified with the use of the biome brush. Previously you had to get exactly the right mix of terrain, plants and objects in each enclosure and relied on text feedback from the zookeepers to let you know what was missing. Now you simply choose the correct biome, or environment, for each animal and paint the enclosure - the correct mix of terrain and plants is automatically filled in.

These streamlined changes don't mean challenge is removed from the game, however. You'll still have scenarios where you'll need to achieve certain objectives and there are campaigns that link a whole series of scenarios together. But in a nod to the younger family members who just want to make a zoo, there's a new freeform mode with unlimited cash so you can just let your imagination go wild. And for older kids there's the Zoopedia, which provides more detail on each animal in an online encyclopaedia.