The age of exploration has long since passed, but that isn't stopping Ubisoft from venturing to new horizons with its ANNO strategy series.

This bold iPhone conquest could be seen as the next logical step for the franchise after a successful excursion on DS, and it certainly extends the tradition of quality gameplay. Rather than cramming multifaceted strategy onto iPhone and iPod touch, though, Ubisoft has instead chosen to create a different experience altogether.

Instead of taking control of an budding empire, you're tasked with the seemingly simple challenge of operating a busy harbour. This involves assigning dock space to commercial ships and fulfilling the desires of passing traders, with everything being controlled via blissfully straightforward touch controls.

High seas trader

In each level you're presented with a static view of the harbour itself. Passing merchants appear as icons at the top of the screen to be dragged and dropped on a free dock in order to unload their valuables.

Once they've unloaded their goods, they request other items. Wood, bread, cloth, spices, and pearls must be taken from the harbour's storage house, which is located in the bottom-right corner of the screen, and deposited onto trading vessels.

Selling a particular item to a trader is just as easy as getting them to dock in your port: drag and drop. When the loading process is complete, the ship will leave and open up a berth for another keen merchant.

Each level takes place against the clock and you have a set cash target to reach in order to complete the stage. As the difficulty ramps up ANNO: The Harbor becomes a fraught and frantic race to manage goods and keep the steady stream of traders contented.

You see, keeping a merchant waiting only serves to frustrate them: once they've had enough they will turn around and leave your port, taking their commodities and cash with them.

The customer is always right

It's imperative that you keep a close eye on what goods are in demand and what you have in your inventory, especially on the later levels when you're charged with managing several different items simultaneous.

For example, it's no good allowing merchants to dock who can only offer nuts when what your other traders are crying out for is spice. The fact that you have to contend with both small and large vessels - both of which have different dock space requirements - only serves to make the process more taxing.

Not that such testing gameplay is a problem - quite the opposite, in fact. ANNO: The Harbor may seem like a fairly stale concept on paper but after a few minutes you are totally and helplessly hooked. Juggling the various traders and ensuring that ships enter and leave the port as quickly and efficiently as possible becomes an obsession.

A good pair of sea-legs

Lush presentation, excellent visuals, and a truly rousing soundtrack - the whole experience is as polished as the deck of a Royal Navy frigate.

Once you've conquered the 36 levels set across four different locations, the appeal of the game does diminish slightly. Your only option past this point is to return to previously finished levels and better your score. Still, ANNO: The Harbor is a tough nut to crack and you're unlikely to breeze through the game in one sitting.

While fans of the original ANNO games may be disappointed that this iPhone edition deviates so sharply from the tried-and-tested gameplay that has made the series so popular, everyone else will be able to enjoy it for what it is: a stunningly playable title that has been built from the ground-up to take advantage of its host platform's unique control interface.