I hid a game in your wallpaper

That's a desktop. Those are the icons. That's the wallpaper.

In about four seconds I'm going to press three keys and start playing it.

What is a playable desktop wallpaper?

A playable desktop wallpaper is an animated wallpaper that runs behind your desktop icons like any other wallpaper, and becomes a real game the moment you press a shortcut. Not a video loop. Not a screensaver. The same file, doing two jobs, and switching between them on purpose.

I've made fourteen packs of them. Worlds that sit behind your icons being quiet, until you'd rather they weren't.

By the end of this you'll know how that seam works, why it's the hardest part of the whole thing, and why the first version I built lost a two-week argument with an operating system.

I'm Martin, Sam to my friends. There's no studio. There's no team. There's me, a desktop PC, and a very large number of very small squares.

Coast to Coast. Star Cruise. Dungeon Dash. Fishing in Hell. Six Gates of Doom. Fourteen packs now, six worlds in most of them, and every single world has its own music.

None of it is drawn.

I'll come back to that, because it isn't how anybody makes pixel art, and it's the most interesting thing about the way I work.

A wallpaper has one job

A wallpaper has one job. Be invisible.

You're not looking at it. You're looking at a spreadsheet, or a browser, or the seventeen folders on your desktop called "new folder". If your wallpaper ever makes you notice it while you're working, it's failed. It's furniture. And good furniture doesn't ask you anything.

A game has the opposite job. A game exists to take your attention and keep hold of it.

So a playable wallpaper is two products that want each other dead, sharing one window.

The first version I built didn't solve that. It let both of them happen at once and hoped.

A fortnight of losing arguments with Windows

I started with off-the-shelf wallpaper software, and I hit the wall inside a day.

One of them does mouse input beautifully and treats a keyboard like a rumour. The other one will take keyboard input — and the moment you switch that on, it hides every icon on your desktop. Which, when the whole pitch is that the world runs behind your icons, is a bit of a problem.

And Windows doesn't want you doing this in the first place. The desktop isn't meant to be an application. Press Tab and Windows takes focus straight back off you. Alt-anything and you're somewhere else entirely.

I spent a fortnight losing arguments with an operating system. It won all of them.

The fix took a proper rewrite, and it wasn't clever. I stopped asking the desktop to be a game. I built an application that sits at desktop level and forwards the keyboard and the mouse into itself — deliberately, on purpose, because it's been told to, rather than by accident.

So the world is genuinely behind your icons. It genuinely answers when you press something. And it's genuinely quiet the rest of the time.

That's the seam. It isn't a graphics trick.

It's a decision about who's allowed your attention, and when.

And the switch is three keys. Ctrl. Alt. P.

Ambient while you're working. A game when you're not. Nothing in between — because in between is where wallpapers go to be annoying.

Nothing here is drawn

A pack is six worlds. Not six wallpapers. Six worlds, each with its own palette, its own things to find, and its own piece of music. And every one of them has to work underneath about forty desktop icons without turning into soup.

That's the constraint that decides every art decision here. Detail in the middle of the screen is wasted. Worse than wasted — it's noise, because there's a folder called "admin" sitting on top of it. So the composition gets pushed out, and down. Movement lives low and at the edges, where your icons aren't. Contrast comes down, not up. A wallpaper that's shouting is a wallpaper you'll turn off by Wednesday.

Now here's the part I want to be straight about, because it's not how you think this is made.

Nothing here is drawn. There's no pixel editor. There's no tablet. Every pixel in every one of those worlds is placed by code — a line that says put a block of that colour, two wide, one tall, at that coordinate — a few hundred of those, stacked up, and a figure appears.

The whole drawing engine is one function:

function px(x, y, w, h, c) {
  ctx.fillStyle = c;
  ctx.fillRect(Math.round(x), Math.round(y), w, h);
}

That's it. That's the entire brush. And then a person is just a list of rectangles:

px(-6, -12,  5, 12, pant);    // left leg
px( 1, -12,  5, 12, pant);    // right leg
px(-6,  -1,  6,  3, C.dark);  // boots
px(-7, -26, 14, 15, vest);    // torso
px(-7, -26, 14,  3, vd);      //   shadow under the collar
px(-2, -24,  4,  9, vd);      //   the seam down the front

Six lines and you can already see him. A few hundred more and he's walking.

And I don't write most of that code either. I describe what I want, a machine writes the function, and then I look at what came back.

That's the job. Looking at what came back.

Here's one. Wisp — the hooded one, we'll get to him properly in a fortnight — has a cold rim of light down one edge of his cloak. First version came back as a single unbroken line, top to bottom.

And it looked like a neon strip stuck to a man.

Light doesn't do that. Light catches cloth where the cloth turns — the crown of a hood, the top of a shoulder, where the hem kicks out. So it got broken into three pieces, in those three places, and then it read as a person standing in the moonlight instead of a person standing next to a light bulb.

That took a lot of goes.

I didn't type most of it. What I did was decide it was wrong, and decide what wrong meant, and keep deciding until it wasn't. Every world in this catalogue is the survivor of a few hundred of those.

Four finished worlds this year didn't get through it. That's a story for another day.

Sixteen colours

Sixteen colours, as a rule. Sometimes fewer.

Not because it's authentic — because sixteen colours is a machine for making decisions. You can't fix a bad composition by adding another blue if there isn't another blue. You have to solve it with shape, and with value. Light things forward, dark things back. Same trick painters were using four hundred years before anyone had a desktop to put it on.

Music that survives four hundred listens

The music's the same story, and I'll say it plainly: I build the tracks with an AI music tool, from my own prompts and my own lyrics. There's a page on this site that lays out exactly what's made how, and I'd rather you had it from me in week one than found it in week nine.

What's mine is the brief. Every world gets a loop that has to survive being heard four hundred times. That's a different job from a game soundtrack. A game track has to be exciting. A wallpaper track has to be good company.

Those aren't the same thing, and it took me six months and a lot of binned tracks to work it out.

And every world has things to find. Small warm glowing things, tucked into the corners — the parts of the scene nobody looks at.

I put one of those in every world for ten months and never once asked myself where they came from.

That turned out to be a mistake. A useful one.

I went looking

That's the first episode of Behind the Icons, and it went up today.

I opened every world I've built, in the order I made them, looking for a thing I never decided to put there. It's about eight minutes, and it's the closest I've come to explaining what this actually is.

Watch: I never asked where they came from

New episode every fortnight.

Try one

No launcher. No separate install for each world. No second window.

It's the wallpaper. It was always the wallpaper.

Fourteen packs. Twelve at £2.99, yours forever — no subscription, nothing to unlock, no nonsense. And two of them are free, permanently, because I'd rather you had one on your desktop than not.

The two free packs are on the Microsoft Store. Put a world behind your icons and see whether you still want it there on Thursday.

That's the only test that matters.