Probably the best Total War to date, and almost certainly one of the greatest strategy games ever.
Tactical strategy is good; there is significant difference between different types of countries, with Western strategy being radically different from that of Eastern factions, for example, which adds a good variety of battles in the game. cavalry are, as ever, overpowered against most troops, but most countries have a good focus on spearmen to counteract this, and the game's forces are superbly balanced despite the different focuses of each faction allowing a player to suit their own play style (the English have the best bowmen, the French have great mounted forces, etc.). So the usual great tactics on the battlefield here, although historic changes have obviously removed some of the more interesting unit types from the game, notably phalanxes, (but there are still elephants!) and have limited the effectiveness of others.
There are a few newer innovations in this game compared to Rome which put a unique spin on things. There is a greater focus on heavy infantry. But most important are the gunpowder units, which have a tactically significant and historically accurate effect on morale, with the long range of cannons changing the face of warfare by the end of the game. Particularly fun to play with are the Turkish naphtha throwers, the missile launchers (oh yes) owned by various Eastern countries, and the elephant artillery.
However, I see the most notable change made as the massive improvements made to the landscape. While in previous games, landscapes were generally bland, enhanced only by the presence of high and low ground, of water in the form of seas and rivers, and of cover from trees. this game adds enrichment in the forms of farms, miniature castles, stone circles, watchtowers, small villages and farms which impact the positioning and movement of troops. additionally, the cliffs and ravines occasionally seen further increase the excitement of manipulating your troops against the enemy, while the fine detail of hand-to-hand troop combat remains a marvel, drawing you further into the reality of the game.
On the strategic (world map) level, the basics are again the same as before. Towns and castles are introduced as separate settlements conveying distinct advantages, and a few extra dynamics such as merchants try to add something new. If the simple crushing of neighbouring countries (who may all be at war with you at once if you're not careful – the diplomacy of the game is tricky to handle and the AI is often illogical) proves too repetitive, then there are Crusades, massive invasions of Mongols and of Timurids, and the invasion of the New World to experience as well. Overall, an enjoyable campaign with superb replay ability as different factions and very satisfying, as their unique starting situations and combination of units creates a novel experience each time.
So overall, it's not as revolutionary as Rome Total War was at the time, but it's a marked improvement in the series, and the strategy is superb. What is more, it is largely historically accurate, but this will be the last of your praises for such a developed strategy game.