In Arthur Conan Doyle’s classic detective stories, there was only one man who truly matched (and even surpassed) Sherlock Holmes’s ingenuity and intellect. No, it wasn’t his arch-nemesis Professor Moriarty - it was his brother, Mycroft Holmes.

In a similar way, if you want to find an App Store title with as much depth and intelligence as Romance of the Three Kingdoms, you need to look within the same gene pool.

Nobunaga’s Ambition is another slice of historic Asian strategy from Koei, and it’s just as brilliant.

Family feudal

This time the setting shifts back to Koei’s home country of Japan. It’s the middle of the 16th century and control for feudal Japan is divided among dozens of bickering warlords.

The game is named after one of these men, Nobunaga Oda, who in reality managed to unite Japan (or at least his clan did) through an ambitious campaign of conquest. Despite this fact, however, you’re free to take control of any of the warlords starting from any of the three chapters on offer.

Nobunaga’s Ambition bears a number of similarities to Romance of the Three Kingdoms Touch, as you'd expect. Like that title, this is a turn-based strategy game predominantly played on a zoomed-out, colour-coded map.

Your goal is quite simply to turn every last section to your colour. This involves diplomacy, resource management, subterfuge, and – most importantly – military force.

Samurai showdown

The decision to pick a fight with a neighbour (you can only invade directly adjacent territory) is not one to be taken lightly. First, you must decide on how many troops you’re able to commit to the endeavour, which requires sufficient food and money to fuel your army.

Even if you’re confident you can win a battle, you have to consider what life might be like post-invasion. Will you have enough men left standing to fend off the attentions of an opportunistic neighbour? Will you leave your starting point vulnerable to attack in the process?

My first invasion as history's bad boy Nobunaga was successful, but resulted in my forces being stretched thin. I swiftly lost my original territory and it took me some time to win it back. It was a hard lesson in patience and the need for proper planning.

Combat itself is a surprisingly straightforward turn-based affair. You take turns to move your cavalry, infantry, and riflemen, attacking when next to an enemy and protecting your commander.

This too is very much like Koei's previous effort, but simpler and more streamlined, which makes it a little less rewarding in the long term.

Nippon the App Store and buy it

In fact, Nobunaga’s Ambition is considerably more accessible. While this approach makes the battle sections less involving, it pays off elsewhere.

I criticised Romance of the Three Kingdoms Touch for being a little unwieldy and counter-intuitive. Nobunaga’s Ambition addresses this directly. There’s still plenty of scope for open play – you can attempt to assassinate rivals with ninjas, sabotage their food supplies, or even propose an alliance - but the game is easier to play and steers away from needless complexity.

Admittedly, it manages to trip itself up with a rather unfinished tutorial section and the last game's on-hand Help menu is sorely missed. Fortunately, you should be able to find answers to most of your questions with a little experimentation.

Nobunaga’s Ambition is another excellent slice of historical strategy from Koei, working along similar lines to Romance of the Three Kingdoms Touch. It’s considerably easier to get into at the expense of a little depth, and if you’re looking to dip your toes into something of real substance, there’s no better place to start on iPhone and iPod touch.