When western naturalists first came across the duck-billed platypus, they thought it was a hoax, cannibalised from parts of other animals by the Chinese. It was a beaver with a beak, a rat that laid eggs, a guinea pig with flippers, a hamster with venom. It made no sense. And yet it did, because it was clearly thriving.

Furbies are a bit like duck-billed platypuses. Are they owls? Are they rodents? Are they mogwai? Are they as evil as their implacable expressions make them seem, or are they good? They make no sense whatsoever, and yet several tens of millions of receipts demonstrate that they're doing just fine.

Given the age of its target audience, you'd be forgiven for having bet on Furby Island being a lazy cash-in on the insanely successful franchise, so when it took the Best Licensed IP gong at 2007's IMG Awards we collectively raised our eyebrows and scrambled to get hold of a copy. Having put in a dozen hours or more, we're ready with our verdict.

The ultimate goal of the game is to host a huge party on Furby Island by assembling the necessary equipment and paraphernalia, a process that entails a series of errands. The island is fairly small, and your interactions with non-player characters are limited to being told what to do next, but that doesn't mean you can just blast through this one.

Furby Island is at the same time very superficial and very deep. There's a huge number of objects and comestibles available to pick up from your surroundings or buy from The Shopkeeper, and there's an even greater range for you to concoct with the ingredients and parts you pick up. A single bed, for instance, requires nails, oak, and fabric, while orange juice demands oranges and sugar, all of which you have to find yourself.

Because your Furby has to level-up, gaining experience as well as physically growing, it's often necessary to carry out tasks that are only tangentially related to your mission in order to develop to the point that you can proceed. For instance, you have to become a competent enough cook to buy strawberries to give to The Sportsman, drawing a mission that might last 60 seconds out to however long it takes to level-up. It's a clever mechanic, forcing you to engage with the gameworld and manage your resources cannily.

There are almost 80 objects and foodstuffs for you to make, many of them with components you can only obtain with experience, so getting to the end of Furby Island takes time and involvement.

Adding a further layer of depth to the gameplay is that fact that your Furby requires constant attention, without which it regularly passes out through boredom, fatigue, or hunger, like an overworked chain-gang member. A small chart at the bottom of the screen keeps you apprised of its condition.

To feed it, you need to buy food from the shopkeeper, with a limited diet of oranges and potatoes available in the early stages. You learn how to eat more sophisticated and expensive food as you gain experience. To entertain it, you stop every now and then and choose the musical note from the range of options, whereupon it whistles to itself for a few seconds and recovers a bit of its joie de vivre.

When your Furby's tired, you need to take it to bed, but since it ends up there anyway when it passes out you're best off ignoring this aspect of its well-being and letting nature take its course.

Indeed, during the early stages particularly, when it's difficult to amass significant levels of satiation, restedness, or happiness, you'll find that the effort involved in keeping your Furby ticking over is greater than just letting it pass out, and its relapses are more of an inconvenience than a compelling feature of the game. If you're kindly disposed towards Furbies, you might find that you're taking better care of yours than we were inclined to, but the game itself gives you little reason to be nice.

Actually, despite Furby Island's huge scope and ambition, the game loses a little of its gloss in the execution. To give one small example of what we mean, keeping your Furby entertained is just a matter of pressing a button. It's an idea, rather than a piece of gameplay, and a missed opportunity, surely, for a mini-game in which you get to interact with the sprite you spend so much time shoving around.

Likewise, it's all very well that you have to make the objects you use, but doing so rarely involves much other than pressing the button that says 'create'. Somebody asks you to make five bottles of orange juice, so you look up the ingredients, make the necessary tools, obtain the ingredients, and combine them, all through a text-based interface.

Aside from the elementary timing-based mini-game that you have to play in order to gather objects from the wild, Furby Island is largely an exercise in following instructions, and some of its demands – that you can't prepare food outside your house, for instance – run the risk of being pedantic rather than rewardingly thorough.

Nevertheless, Furby Island's little world pulsates with colour and scampering life, and we haven't had space to cover one tenth of what it contains in this already over-long review. Our criticisms shouldn't put you off buying it if you're remotely interested in games like The Sims and Nintendo's modern classic Animal Crossing, amongst which company it sits on equal terms.