But one of the reasons this system is so smart is that it’s not as simple as that. For one thing, you can switch your choices out freely at Gene Banks all over Rapture, so there’s masses of room for experimentation and variety. And because Tonics aren’t restricted to dry numerical increments, they get wonderfully exotic. To give you some idea of how distinctive you can make your character with these, we focused our character so tightly on hitting things with a wrench that by the end of the game, we could brain any unsuspecting enemy with a single swipe.

In addition to learning these strange new skills, the main thing you discover during the early sections of the game is Rapture itself. It’s an incredible experience, and the first of three big reasons why BioShock is very special indeed.

The sound designers deserve a huge chunk of the credit for this. Think of the first time you set eyes on a game like Far Cry, and imagine the audio equivalent. It’s exquisite, not just in setting the powerful ambience of Rapture, but in evoking the crackling, fizzling smack of combat. And as if for an encore, the acting is perfect - sometimes uncomfortably so, given the gruelling themes. There’s even a plot twist that hinges on one voice actor sounding natural when saying something very deliberate, and they pull it off. It’s hard to imagine another game being able to trust their talent witha trick like that.

Despite what you’d assume to be a limited visual palette, Rapture’s districts manage to be sumptuously diverse. We found ourself dreading to leave each area because the next couldn’t possibly be as gorgeous - and we were wrong almost every time. You’ll trudge through bristling green gardens, rusty wharfs, frosty white ice halls and infernal factories choked withamber smog.

And yet every scene in Rapture has the same three clashing forces. Firstly: the water. It drips from cracks, seeps through ruptures, gushes out of burst pipes, washes in swells across the floor, crashes down stairwells in a flurry of spume. A city under the sea is a defiance of nature, and nature’s encroaching response is rendered beautifully.

Then there’s the sheer sense of hubris: the neon optimism, the cheery posters and glib commercials. “My daddy’s smarter than Einstein,” a child’s voice chirps from a Plasmid vending machine. “And stronger than Hercules! And he lights flame with a snap of his fingers! Are you as good as my daddy? Not unless you visit the Gatherer’s Garden!”