Close followers of science fiction literature undoubtedly know the tale of Ender and his xenocidal game. Each blast of his simulation space fighter taking out another digital foe without knowing that each blow was one step closer to destroying an alien race.

To think, swipes of your iPhone's touchscreen could signal the annexation of a new world or doom a rival fighter squadron. Galcon feels like Ender's Game come to life without the moral ambiguities. It's simple, entertaining, and pushes expectation with its multiplayer options.

The screen displays a 2D map of planets, with size indicating their production rate. Simply put, the bigger the planet the faster it produces. A number above each body informs you of how many ships are available.

You start with a single green planet against one opponent, and your job is to conquer them all. How? By dragging your finger from your planet to others to send swarms of ships (represented by little triangles) to take them over.

There's plenty of strategic thinking to be done around that. You can choose several planets or fleets at a time to attack – sending a huge mass of ships to blat your foe's home planet is particularly satisfying. Alternatively, you can annex several planets in a simultaneous endeavor. You can tweak the percentage of a planet's ships sent to attack by tapping on a percentage figure at the bottom of the screen. How you work with these options is up to you.

Galcon offers five difficulty levels, from Cabin Boy to Captain, and a variety of different modes. In Stealth mode you can't see enemy fleets, for example, while the Vacuum option tasks you with conquering all the planets before a timer runs out. Beast is about as frightening as its name, while 3-Way has you competing against two opponents rather than one. There's plenty of variety to be had, and quite a challenge judging by our woeful performance when we attempted Captain level.

Then there's multiplayer (introduced in version 1.2 of the game) which lets you test your interplanetary conquest skills against other players over the network. The set-up process is a bit fiddly, in that you have to register a username on the game's official website from a desktop computer, then enter details in your iPhone's Settings menu.

However, once set up, you just tap the Net Game icon on the main menu, choose an available server (or a local iPhone), and away you go. There are even rankings, although the game's developer is currently seeking help to improve them.

We sometimes moan about the App Store being clogged up by rubbish sudoku and Breakout games made by bedroom coders, but Galcon is one of the games that vindicates Apple's open-door policy. It's a genuinely innovative game that uses the iPhone's touchscreen and connectivity well, and is clearly evolving based on the feedback from its player community.

As a solo game, Galcon might lose its appeal after a few weeks. Nevertheless, the constant challenges posed by human opponents, not to mention the developer's obvious commitment to regular gameplay updates, should mitigate against that and make Galcon one of the breakout hits of the App Store.