The first thing the publishers of Sid Meier's Civilization IV: Beyond the Sword will want to tell you about their new expansion pack is that it offers far more than a typical add-on disk.

The great news is that they are right, and Beyond the Sword is shaping up to be a fantastic boon to anyone who has exhausted the century spanning world of Civilization IV over the last two years. Of course it includes the standard features you would expect any decent expansion pack to incorporate, such as numerous new units, buildings and technologies for the main 'epic game', with a focus on additional content for the gameplay set in the later time periods available.

AI has certainly been improved too, and several new random events to test the solidarity of your empire are included, from natural disasters like tsunamis and fires, to problems with your citizens and social unrest. 16 new leaders have also been made available to test and compete with, ten of which come with completely new civilizations of their own. These ten civilizations include Portugal, the Netherlands and even Babylon, and bring with them a complete new range of unique themed units and constructions.

These additions to the game will definitely breath new life into the original release, and for seasoned fans offer some very exciting changes to the Civ world, but outside of these embellishments of content, the second expansion for Civilization IV also provides an interesting shift in focus that should provide players with a new slant on their beloved god game. Though there have always been a host of other distractions for budding emperors alongside the game's concentration on building and war, the new features in Beyond the Sword allow for all kinds of new distractions from construction and combat.

Corporations are one of the most interesting of these new gameplay features, which introduce the heady world of capitalism to Civ IV. Players can create their own enormous companies and usher them as they spread the virtual world, reaping in rewards for the gamer with a keen sense of commerce, trade and industry.

Espionage, which has featured in previous Civ titles, is now available far earlier on in the development of a society, allowing cunning players to send spies into their enemy's community. These underhanded snoops, who are invisible to all but other spies, can not only observe their rival's development, but also stir unrest and defend their own leader's secrets.

Religion now plays a greater role too, allowing you to develop the infrastructure for a belief network starting with an Apostolic Palace, before spreading the word and forming a mutually beneficial bond with other cultures who share your faith. There are also new wonders to be discovered by players who enjoy the exploration elements of the game. These include several historical landmarks from the Statue of Zeus to the famous Moai Statues.

Advanced starts are another feature that come with the expansion pack, that may sound rather pedestrian, but are in fact an ideal way for seasoned players to tuck into the benefits of Beyond the Sword without having to play through the early stages of the game that they have no doubt encountered countless times before. Advanced starts clearly offer an opportunity for newcomers to short-cut their way to the end stages of a game, and although some will undoubtedly do so, for most the pleasure of a turn-based strategy game will be in playing through a game in its entirety.

Despite all these additions and re-workings of the original Civ IV game model, the most significant still hasn't been touched on yet. The new scenarios that come with the Beyond the Sword expansion pack may not sound like much, but actually almost qualify as complete new games within the Civ universe.

Each presents the player with a new concept, story line, objectives and skin for the proven Civ IV game engine. The 12 on offer each tackle different time-periods and aesthetics, from the historical to the novel, and many touch on themes never yet explored by Civ games. The Firaxis development team has created each scenario, with apparent and significant input by the series' legions of fans.

The scenario demonstrated was a space themed final frontier encounter set deep in the vacuum of the cosmos. Whilst demonstrating Civ's blatant disregard for scale in the pursuit of purer gameplay, it also showed how new mechanics have been developed purely for their scenarios. For example the addition of asteroid belts, which reduce transport speed and increase defensive ability, are exclusive to deep space areas. Black holes and new terrain also exist, along with new units such as space stations, and a completely new technology tree.

One of the package's most interesting inclusions is the mysterious Afterworld scenario, which remains closely guarded. Apparently something like Civ IV with a comic book feel and presentation, just how it will work is unclear. It apparently features no technologies, no leaders and even no cites, and all we know is that it does introduce a grim plot and horrific content.

In general it seems like Beyond the Sword is a thorough and diverse package that does a great deal to create a completely new experience. It may well only be an add on disk, but after a year in development it already looks like an essential purchase for fans of Sid Meier's god games, and can be expected around July this year.