Far more mobile games are made from films than from books, but if you think about it there's no reason why. Playing a mobile game and reading a book both require active input from you, rather than allowing you to sit back and let the entertainment happen; they both involve using your imagination to supply visual and auditory information; and you need to hold them both in your hand.

That's three things.

There are hundreds of books that would make excellent games, many of which we'll get around to covering in this series of articles, but few are more fit for conversion than Roald Dahl's grotesque underground epic Fantastic Mr Fox.

Of course, Fantastic Mr Fox has already had a conversion of sorts, a Spectrum and Commodore 64 game called Fox Fights Back (pictured). It's not a direct licence, no, but what is Roald Dahl's Mr Fox doing if not fighting back against the unholy trinity of Boggis, Bunce, and Bean?

Our game is based directly on Roald Dahl's book, and the publishers reading this will agree that it's a rock solid guaranteed million-selling idea. Here's how it plays out.

Level 1: Tutorial / Boggis.
Welcome to the world of Mr Fox. It's time to forget everything you know about not being a fox, because for the next few hours of your life that's exactly what you're going to be. Your life revolves around four things. Turkeys, geese, chickens, and your family. Your children are adorable and your wife is literally a vixen. You steal things for them. That's just how you roll.

It's time to go hunting. Navigating with the eight directional keys on your mobile keypad, you first need to make your way to Boggis's chicken farm.

Once you get into the chicken shed, all hell breaks loose. The chickens start flapping around, and you need to maul as many as you can before the timer runs down.

Inter-level animation: Farmhouse exterior. A light comes on. A fat man is silhouetted in the window. A pack of dogs storm out through the front door.

Level 2: Bunce.
Armed with a sack of dumplings, you have to make your way to Bunce's goose farm. There are dogs chasing you. Press '5' to throw Boggis's dumplings. The dogs are dazed. You savage them to death.

Inside the goose shed, it's mayhem. Geese are desperately trying to escape, flapping their wings and waddling around. Protecting their young. You chase them, viciously executing as many as possible before your time runs out.

Inter-level animation: Goose shed interior, dark. A door opens. Mr Fox is standing in a rectangle of light. The shadow of a man with a rifle is draped over him.

Level 3: Bean.
Armed with a sack of Bunce's goose liver doughnuts, you have to make your way to Bean's turkey and apple farm. The dogs are after you, and so is Bunce with his rifle. Press '5' to throw goose liver doughnuts, all the while dodging the bullets that climb up the screen behind you. The dogs are dazed. You rip out their throats.

The turkeys are frantic. You kill as many as you can before the timer runs down.

Inter-level animation: Mr Fox, breathing heavily, blood dripping from his muzzle.

Level 4: Home.
At last, armed with a sack of Bean's apples, it's time to go home. For this final stretch, you've got Boggis's dogs, Bunce and his rifle, and Bean in his tractor all hot on your tail. Press '5' to throw an apple. The dogs are stunned. You can either smash their brains in or leave them to be pulped by the tractor. Either way, it's absolutely crucial that you get home in one piece.

Inter-level animation: Your tail gets shot off.

Level 5: Going Underground.
You may be home, but Boggis, Bunce, and Bean are determined to kill you, whatever the cost. No sooner are you underground than the ceiling starts to shake. It's time to dig.

Use the directional keys to navigate and '5' to excavate a square of earth. Watch out for boulders, and make sure you don't get squashed by falling earth. The deeper you dig, more oxygen you need. Collect 'oxygen parsnips' to prolong your life.

Congratulations! You've won the game. You're too deep for Boggis, Bunce, or Bean to reach you with their digging machinery, and so you have carte blanche to steal their produce forever!