One big problem remained. A doctor stood to the left of my hospital bed, blinking. Behind him was a drip stand, also blinking, its pulsating red light fastidiously metering out the vile chemotherapy that heroically dribbled through a needle and into my vein.

A painfully aloof cancer was ravaging my left leg: osteogenic sarcoma. This was a rare and sophisticated network of malignancy with a big appetite and a tight schedule. The doctor noisily blinked once more. The odds of saving my left leg were as thin as the bone that once grew there.

The best-case scenario was the installation of an "extended prosthetic knee". Which to the ears of my 12-year-old self sounded pretty mint. Then there was option B. This choice was called "amputation". I'd seen enough pirate films to know that it required me to bite on a stick and do all I could to not scream. But thanks to the colourful array of medical drugs I was on, with names that jostled like dinosaurs, I couldn't even eat soup without vomiting, let alone keep a twig between my teeth. That option seemed flawed.

Finally, option C: the deluxe package. This was just straight-up death, possibly via a peppering of pulmonary tumours. Option C was even more of a metaphysical mouthful than what'd come before. So my pre-pubescent brain filed this eventuality in a compartment labelled: "that sounds weird".

To the right of the hospital bed stood my immediate family: my stunned parents, and my numb siblings. Stoically, they also blinked. Then we all stared hopefully towards the frozen TV that clung to the wall.

I sighed. Then I gave my big problem my undivided attention. I couldn't get Sonic the Hedgehog to defeat Doctor Ivo Robotnik at the end of level five. Star Light Zone was simply too hard. I craved to liberate the animals of South Island from their mechanised incarceration. It's all I had left. Picking back up my black Sega controller, I un-paused Sonic from his mid-air leap and vanished from the oncology ward once more.

Unlike the rest of my life, things were flourishing with Sonic. Yes, my hair kept falling out of my head and into my lunch, which was not cool. And I couldn't walk, constantly dreading the repulsive gauntlet of school life on crutches. I hadn't spoken to a girl in years and puberty was hiding furtively somewhere else in this hospital. But once Sonic was rolling, I was free. This hedgehog's gallant bounds made life palatable the moment the pad hit my palms.

I loved Sonic and his perpetual energy. This gaming obsession warmed my sepia hospital room like a sunrise.

My classmates from a strangely distant high school in Macclesfield had philanthropically donated a Mega Drive. It was a gift to commemorate my contracting of cancer and to aid me in the art of distraction from bone saws, spinal epidurals, the cavalcade of vomit bowls, endless needles and the lingering bruises from failed cannula sites.

The plan worked. I loved my Mega Drive. I loved Sonic and his perpetual energy. This gaming obsession warmed my sepia hospital room like a sunrise. Regardless of what exotic brew of chemotherapy they dosed me with, or whether I lay in my home bed or a medical bed, the only true constant in my life was that hyperactive hedgehog's defiant smile and spinning red sneakers. As I boisterously hammered the controller, all thumbs and mutters, the chemo needle wiggled painfully in my forearm. Like a spur in a horse's flank, each noxious twinge hurled me further into a pixelated world of escape.

Days whispered into weeks. Weeks exhaled into months. The more needles that went into my arms, the more I curled up. Morphine entered my spine, but I simply became one with my blue hero. Hickman lines were inserted into the top of my heart to radically accelerate the chemo hitting my blood. In defence, I imagined myself a ball, bristling with 500 sharpened quills.

It was the nurses that first complained about my mania with speed – an obsession further fuelled by the availability of a wheelchair. I sped round corners, terrorising porters and playing chicken with lane-hogging beds. I just couldn't stomach the inertia that made me visible.

I began to recreate the slopes, loop-the-loops and jumps of South Island. Using nothing more than hospital ramps, a wheelchair and my own belligerent momentum I liberated myself. Thundering down the sterile corridors, my wheels red hot with hope, I craved the blurring colours of flight.

The grey pain of NHS reality urged me deeper into this Technicolor warren. Mechanised wasps stung me with medical lasers. Armoured bugs fussed towards me in motorised cyclic loops before scurrying off. I scratched away my opiated, itchy dawn dreams by pressing restart.

The 'ching!' of shiny rings sponsored an assumption that if I could just gather enough of them then I could win another life. Or at least salvage half a leg.

My doctor's slippery behaviour started to mirror Robotnik's own evasive presence at the end of each level. I'd stumble upon him, quietly laying in wait for me, before unleashing increasingly toxic concoctions into my circulation.

An acrid metallic taste took over my mouth. The methotrexate they plied me with popped me further out of my body as this journey descended ever deeper into a mechanical, bionic hell. I was compelled to push on further towards Scrap Brain Zone and the final reckoning. The quest for the six Chaos Emeralds had become a mortal wager.

Often I had to pause. This pinball world became drenched in nausea. My throat burned with acid as old industrial pipes flared with fire on screen. Lifts patiently ferried me up and down the levels. I bounced across the TV sets of static that raged into the white noise of infinity. My azure avatar chased the sparkle of fleeting power-up invincibility that seemed my only hope to survive.

I drank golden hoops at supersonic speed. The "ching!" of shiny rings sponsored an assumption that if I could just gather enough of them then I could win another life. Or at least salvage half a leg.

Dr Eggman's trail of golden halos teased me on. Podiums appeared, podiums dissolved. I leapt boldly over chasms that would seize an entire life. Hopping between lava beds and feinting past thrusting, syringe-like spikes I charged towards an industrial atrium that hissed with septic funk. Once there I calmly awaited the boffin and his final reckoning. My foot tapped nervously.

Eventually the doctor emerged, bustling manically around the room with all manner of instruments and cronies. I balled up, bounced and thrust every spike in his direction. His attacks stung. My body flashed. A 16bit soundtrack blared mindlessly into the future. Then, eventually, silence. A lot of blinking resumed, both on the screen and off. Nerves shattered, Sonic's smog of pixels began to disperse. His lurid colours faded. The hum of a hospital resumed.

A fox flicked off the television set. Then stared me down benevolently, cast open the curtains before prattling on brightly about my stitches. Stitches? I'd had my operation? The fears of amputation tore through my mind. I struggled up in bed, looking blearily towards my toes in panic.

My mind flashed through a dozen shades of relief. I clearly had two feet.

The needles, drains, pipes, quills and cannulas retracted, and I realised I'd conquered South Island. The Chaos Emeralds were mine.

One left leg wallowed in bandages like a fuzzy white zeppelin far up in the sky. This frozen white of cloth was completely numb. I couldn't feel a thing, but it certainly wasn't any shorter than the right leg. In fact, it looked much longer, but perhaps that was the morphine being sneaky again. Either way, regardless of the shared occupancy of titanium knees and fleshy junctures it was still very much attached to me, as I was attached to it.

Then all the needles, drains, pipes, quills and cannulas retracted and I realised I'd conquered South Island. The Chaos Emeralds were mine. The mechanical terror of Dr Robotnik was vanquished and I didn't have to chew on any sticks in the process.

Perhaps the next game was tracking down my abstracted puberty lost in this hospital over the last 18 months. Where did that fox just scamper off to? Was it a nurse? Or was it Miles Prower, aka Tails, come to fetch me for the follow-up adventure.

According to the consultants, one in six cancer sufferers face their tumours for a second time later in their life. But I barely even cared, as I was all set for Sonic 2.