I had a discussion with a friend the other day about the ever-changing nature of computer gaming.

He was of the opinion, and I have to agree, that as communication technology moves forward at an astonishing speed, our attention span seems to be diminishing in proportion. What passes as entertainment these days is vastly different in scope and quality to what previous generations enjoyed, and we expect it in small, bite-sized pieces so we can absorb it faster, and pass the message on to others. Why write a letter when you can email? Why email when you can twitter?

Anno 1404 is about as far away from this brave new world as you can possibly imagine. It's reminiscent of a age when you could come home from a hard days work and look forward to the quiet enjoyment to be had in adding another five pieces to your ongoing jigsaw puzzle, or perhaps assembling the canopy on a balsa-wood aeroplane model. Slippers optional. In fact, if you have no recollection of the Anno series (which is now over a decade old) you'd be best to read our retrospective article before progressing any further.

Anno 1404, confusingly, is the fourth in the Anno series, having followed Anno 1701, Anno 1503 and Anno 1602. Each release adds a layer of complexity to what is already an astonishingly complicated strategy trading sim. The series underwent a major overhaul in 2006, with Anno 1701 leaving behind dated graphics and limited campaign options in favour of a much more detailed game world, technology tree and AI. Anno 1404 now continues that trend, and is every bit the leap forward that the series deserves.

From humble beginnings you're tasked with carving out your own slice of an early 15th century trading empire in a land heavily divided between Western ideology, and Eastern doctrine. As with all Anno releases, you can choose between embarking upon a series of campaign games that gradually introduce new gameplay concepts, or you can simply select "continuous play" to allow you to customise your game world and winning conditions. Both options have been considerably enhanced over the previous 1701 game, which will come as no surprise once you begin to see just how many new features have been implemented this time around.

Fundamentally, Anno is about production, and efficiency. No surprise then, that developers Related Designs hail from Germany. To grow your colony, your fledgling community will require basic goods such as wood, tools, and food, however they'll soon discover cider, spices and a place to worship are equally as necessary. To satisfy each desire, you'll need to set up some kind of production facility, and some of the more luxurious items require multiple facilities working on multiple islands to produce.

Each production chain, from foresters huts, to glassworks, to date plantations have a specific order of requirement, and are slotted into the game as purposefully and pointedly as selecting third gear in a Porsche 911. Any lack of efficiency is brought to your attention immediately by the ever-busy notification bar, which will point out glaring problems such as a lack of storage space, or a trade route that isn't optimised. The more goods you produce, the higher the population you can support, which in turn will provide you with enough tax revenue to produce an army, and clean out the opposition. At its heart, any game of Anno amounts to one basic concept - whatever is demanded, must be supplied.

In the case of Anno 1404, the demand is staggering.

Where 1701 had perhaps a dozen core base resources that could be collected to produce perhaps eight or so requirements that needed to be finely balanced to satisfy each tier of citizen progression, 1404 has dozens. Not only that, they're cross-referenced with each other, and often form only part of a complete requirement for each citizen level. Confused? Well, in Anno 1701 your population demanded alcohol from early on in the game in order to grow. In 1404, they'll still demand alcohol, but both cider and beer needs to be provided to allow progression. Either beverage by themselves will prevent a riot, providing they're adequately supplied, so there's far less concentration on providing a stable supply of one good, and more of a shift towards seeking chains of supply for future expansion. This carries over to building requirements too - eventually your chapel won't be sufficient, and you'll need a church. Whereas previously you could demolish your chapel and build a church to keep everyone happy, in 1404 both are required.

This alone is probably the biggest alteration to the series, and fortunately, it's a positive one. All too often Anno 1701 would reach a tipping point where your supplies of any one item would rapidly dwindle, requiring you to scrabble about and hastily construct additional facilities with limited funds to prevent your entire colony from going bankrupt. It just so happens that 1404 has taken this refined juggling act even further with the introduction of the Oriental faction, which adds yet another twist to keep veterans on their toes.

In all previous Anno titles, production was split between northern and southern hemispheres, with most goods only capable of being grown on each particular latitude. In 1404, the southern islands are classified as Oriental, and in order to build an Oriental colony, you'll need to trade with the Grand Vizier. The Grand Vizier is much like 1701's Free Trader in the respect that you accept quests and participate in trade, although instead of earning simply cash and item rewards, you'll actively earn the ability to upgrade Oriental-specific production facilities and town buildings through a newly introduced honour system. This participation is compulsory - you can't simply sit back and view the world through Western eyes, as your citizens will demand items that can only be sourced from the Orient.

Moving resources from island to island requires a comprehensive merchant fleet, and for the first time your vessels can be individually upgraded with various tokens acquired through trade or completing quests. You can equip an individual vessel with faster sails, or a larger hold, or perhaps the ability to be repaired at speed - the choice is up to you. Warehouses too, can be modified in a similar manner to aid you in your production or storage capacity. This mechanic has replaced the technology tree from 1701, and whilst I believe 1404 is actually more cohesive in this respect, I can't see why both couldn't have been included.

If you're looking for a game to hone your military skills on, you're not going to find it here. You can build and train units in a similar fashion to what you would expect from Age of Empires, for example, but their deployment is expensive, time consuming, and only really something for end-game, or if you particularly need a certain island to expand your production. Naval battles are enjoyable to watch, but again, each ship you lose costs you money and puts you further behind your competition, so you might be better off simply making peace with your enemies and concentrating on trade.

Visually, 1404 is a masterpiece. You won't tire of the animation, and the detail inherent in every production facility, ship, palm tree and wave crest will delight even the most hardened cynic. Minimum system requirements are specified as a Pentium 4 3.0GHz with a 128MB DirectX 9 compatible graphics card and 1GB of RAM, and our review machine with a 3.0Ghz quadcore, 2GB of RAM and a 512MB 9800GT had no problem on the maximum settings. The images in this review were lifted directly from the game.

Problems? Well, there are a few. Loading times for saved games are excessive. The continuous play option will be unfathomable to anyone who hasn't played through the campaign mode, or spent a lot of time playing Anno 1701, and to be honest, the game doesn't do a particularly good job of explaining itself. There's no multiplayer either, and while this might sound like a terrible loss, Anno has never really lent itself towards either LAN or internet play. I have a saved game on 1701 that I've been playing for 140 hours, and I can't think of a single human being who would want to multiplay a trading sim for that period of time. Marco Polo, perhaps?

I'm sorry to say that the DRM on 1404 is about as bad as it gets, with only three installs possible and internet access required to install the game. Anyone who seriously enjoys this game will be playing it for years, so this requirement is baffling and we can only hope Ubisoft come to their senses and remove it with a future patch or expansion. This type of poor judgement will only serve to alienate legitimate purchasers and encourage piracy, and it's a shame nobody seems to be learning from EA's mistakes in this regard.

So bottom line - if you've never played Anno before and you're quite interested in RTS titles that require a huge time commitment, go and grab Anno 1701 first. It's a fantastic game in its own right. Once you've gotten the hang of that, or you're already a seasoned player, pick up 1404, because it has the additional features and modifications that stretch out the franchise and provide the type of gameplay simply not offered anywhere else.