The term 'real-time strategy' is such a catch-all description that it's essentially meaningless. Take Amoebattle, for example.

At its core it's a real-time strategy title, but there are no tanks or planes involved, and while its battles occur without pause that's as close to reality as it gets.

Instead of building units, your single-celled warriors can split themselves in two when they've eaten enough food, and the whole game takes place in a microscopic realm that's being devoured by a destructive virus.

Terrorist cells

You start the game with a single, blobby grunt. After a few scraps and a nibble on some of the flora that spring up on the map you can split your unit into two, doubling your fighting capacity. You have 25 slots in your army and can never have any more amoebas than that.

A chatty AI sets you tasks as you fight your way through the hexagonally derived environments. You'll need to kill a certain number of enemies in order to absorb their DNA, and once you have you can take on their forms and add their skills to your army.

Each level has its own missions, and starts you out with a different number of troops. It's up to you to explore the map, find the resources you need, and protect the points you're told to. Wave-based scenarios add an extra layer of tension to proceedings.

There are different types of amoeba to master, all with their own strengths and weaknesses, and building a balanced army involves splitting and mutating at just the right time. The touchscreen controls are smooth and intuitive, mixing gestures and swipes to good effect.

Protozoic pugilists

With 12 large missions to complete, the game isn't exactly lacking in content, but the absence of a multiplayer mode is disappointing. Things can sometimes be a tad too easy in the earlier levels, too, but some excellent set-pieces later on more than make up for that.

Amoebattle is a fine example of how smartphone games can eschew the classifications and genres into which we traditionally arrange gaming. More than that, though, it's a fun little game that anyone, RTS fan or not, can pick up and enjoy.