Fall of the Samurai is the stand-alone expansion pack to Total War: Shogun 2. For those who aren't familiar with the series, Total War games each examine a particular period of history and through a combination of epic real-time combat and turn-based empire building, allow gamers to rewrite history as they see fit, experiencing tense and chaotic battles as they journey through an alternate past.

Total War: Shogun 2 was released last year to universal acclaim, and focussed on events in Japan in the 16th century. As the title suggests, it wasn't Creative Assembly's first foray into that particular period of history. In 2000 Shogun: Total War was released, depicting key events from the Sengoku period of Japanese history. Both titles stand as landmarks in the Total War series, one for establishing the franchise, the latter for consolidating all that had been learned in previous installments and making the game that many consider to be the finest in the series.

Fall of the Samurai retains the geographical setting of Shogun 2, but the history is very, very different. The game focuses on the 1869 Boshin War; a struggle between pro-imperial modernisers and the fiercely traditional shogunate. The events of FotS take place some 300 years after those of the main campaign, giving plenty of time for the geopolitical landscape to have shifted considerably. In this new historical setting, players are faced with the choice of siding with either the emperor or the shogun. From then on in the player has to use war, diplomacy and intrigue as their tools for expansion over the islands of Japan.

The Boshin War provided the backdrop to the Japanese industrial revolution. Western influence stirred tensions and prompted rapid economic growth. This country-wide change is reflected in FotS's campaign, with armies noticeably modernising as the game progresses. Earlier battles are populated by troops that, for the most part, wouldn't feel out of place in the original campaign, but by the end units are unlocked on the new tech-tree that have never been seen in a Total War game before.

It's not long before the old makes way for the new, and with the improvement of technology comes more efficient, and more explosive armies. Units become more powerful, with better range and improved accuracy. This is also reflected in the campaign map, which later on in the game is populated with ironclad warships, train stations and foreign mercenaries.

The updated campaign map is beautifully realised. Settlements are dotted in amongst rolling hills and mountains, and fields surround the cities. The water effects are pleasant enough, and avatars that represent your armies and agents are distinctive and easy to identify. The map divides Japan into provinces. The basic divide between the various factions is loyalty to the emperor (or the lack thereof). When making most tactical decisions, it is this factor that comes to the fore most prominently. The campaign AI can be most helpful when battling against a common enemy, and on the converse side, picking a fight with one province can cause a hostile reaction from other regions with the same political alignment.

As you progress through the campaign, there is a fair amount of resource management, but it never feels overly intrusive. The turn-based element is deep enough to provide immersion, but it never feels excessive or overly time-consuming. Building a solid empire is essential to success on the battlefield.

As the campaign map slowly turns your particular colour of dominance, maintaining a balance within the confines of your growing empire becomes tricky. Split allegiances and general mistrust often cause isolated uprisings within the provinces you capture. There are some new agents, namely the Ishin-shishi and Shinsengumi, that can incite and suppress political rebellion, though a garrisoned army often provides the same effect. Keeping everybody happy during this decisive period of Japanese history is by no means an easy task.

Despite concerted efforts to keep everyone smiling, it doesn't take long for tensions to boil over into rebellion. Even more so once your territory has increased, bringing opposing factions under your control. The real challenge in FotS's campaign comes in suppressing these rebellions, at the same time as maintaining a concerted push to expand the boundaries of your domain. Finding a balance can be difficult at first.

The normal Total War campaign speed has been dropped to reflect Japan's rapid transition from rural economy to industrial nation, with each year new yielding 24 turns. There is one significant implication to this; winter, and the attrition that comes with it, now lasts for six turns. The penalties for maintaining an army outside of your own borders aren't severe, but the gradual erosion of your forces strength is noticeable when in combat.

When getting to combat the loading times are, once again, considerable. There's plenty of thumb twiddling, so it's lucky that the wait is nearly always worth it. The music that accompanies the long pauses has been very carefully selected. As with so much in FotS, it modernises with the game, drawing in more and more Western influences. It proves to be a complimentary combination.

Combat is intense and satisfying. The detail on every individual soldier retains Creative Assembly's flair for the authentic, and the combat animations when units clash are detailed and varied. Not that there is enough time to zoom in and marvel at the intricate individual skirmishes (made deliciously gory if you download the Blood Pack DLC). For the most part, real-time battles require constant attention; victory is often found by making the little adjustments at the right time.

Once again massive armies line up against each other in a variety of different scenarios, including the usual mix of siege and land battles. Some are more exciting than others. Once the initial novelty has worn off, the naval battles can be laborious affairs. Large turning circles and frustrating targeting makes the sea-based combat more finicky than its land-based equivalent, though it is not completely without merit, and occasionally makes for a well-timed distraction from the usual sieging and conquest.

Naval combat follows the same path to modernisation as the rest of the units in FotS. At the start it's all frigates and gunboats, but by the end the sea is populated with powerful ironclads, armed to the teeth with exploding shells. Naval combat spills over from simple skirmishes and onto the campaign map, and players have the option to use their fleets to bombard coastal positions and harass armies if they move around on coastal roads. It is even possible to use nearby fleets to bombard opposing forces in the midst of real-time battles. It can be wildly inaccurate, but a well timed hit can seriously damage a unit, sending troops flying into the air. A limit of two bombardments per battle stops this becoming an extravagant addition.

Weaponry improves on the battlefield as the campaign progresses. Gatling Guns (complete with the option to drop down into a third-person "gun-barrel" view) take their place next to artillery, cavalry and a variety of different infantry units. Traditionalists can follow the teachings of old and field an army dominated by katana swords and archaic armour, whereas modernisers can quickly and effectively update their forces. By dealing with the West, new technology can be quickly acquired and in relatively little time a modern-looking army can be fielded.

These new units have had an impact on the games all important AI, and Creative Assembly has been careful to balance the strength of these new units with suitable weakness. For example, Gatling Guns are obviously dangerous when dealing with opposing troops directly in front of them, but they are slow to manoeuvre and from the flanks they are very vulnerable.

Once again the AI is very strong. Strangely configurated armies will line up against you from time to time, but apart from that, the computer makes a worthy opponent. It is a game that rewards creative thinking. The decisive execution of a solid tactical plan often leads to victory, and in no series is tactical nous more important than in Total War. Tactics wins battles, and clinging on to this knowledge is essential when approaching the game on harder settings. A stern challenge becomes even more tricky; generals are more creative and decisive, and units become more expensive to recruit, making your own forces scarcer than ever before.

The sounds of war are there and all accounted for. The din of battle sounds realistic, and the ever increasing crackle of formidable gun fire adds to the already polished Shogun 2 atmosphere.

For those who prefer to battle sentient opponents, there are the usual multiplayer options available. New weapons and armour can be unlocked, and there are both head to head and co-operative modes. There's also a new conquest map to reflect the 19th century setting.

Once the campaign has been completed, there are some classic skirmishes to play through. An historical scenario is explained, objectives are given and an army is placed on the battlefield. These missions provide a welcome alternative to the campaign. Although these stand-alone battles are large in scale, they are made more enjoyable as the campaign-induced fear of losing your entire army isn't there anymore; you wont have to rely on these same troops again.

Between the campaign, the multiplayer and the historical skirmishes, Fall of the Samurai offers a wealth of content for gamers to explore. Although it is an expansion pack in name, its size coupled with the fact that you don't need the original Shogun 2 to play, means that this is a complete package in its own right. Exciting new units compliment a tried and tested formula to great effect. If you're looking for a new challenge, new armies to lead and new lands to conquer, then Fall of the Samurai comes very highly recommended.