Ski Slalom

Ski Slalom is an endless downhill run. You start at the top of a slope 36 metres wide, and the hill goes on forever — there is no finish line, only the tree that eventually gets you. Your score is the distance you covered plus whatever you earned in the air.

Controls

Steer with the left and right arrow keys, or A and D. Hold the down arrow or S to tuck. On a phone or tablet, the three buttons under the slope do the same job — press and hold rather than tapping, because steering is a held input rather than a nudge. The first steer starts the run, so you can begin without reaching for the Start button.

Speed, and why turning costs you

Cruising, you travel at 18 metres per second — about 65 km/h. Tucking takes that to 26 metres per second, roughly 94 km/h, and you accelerate into it rather than snapping there instantly. But turning scrubs speed: while you are steering, your target speed drops to 82% of what it would otherwise be. That is the central tension of the game. The fast line is the straight line, and every tree you swerve around is a tax on your distance. Good runs come from reading the slope far enough ahead that small early corrections replace big late ones.

What is on the hill

Trees and rocks end the run. There is no damage model and no lives — one contact and you are done, which is what makes the whole thing a game of nerve rather than attrition. Moguls are the exception: hitting one costs you 30% of your speed but nothing else, so a mogul field is survivable if you are willing to give up the pace. Ramps launch you. For 1.1 seconds afterwards you are airborne, and while you are in the air nothing on the ground can touch you — a ramp in front of a stand of trees is a shortcut, if you are brave enough to take it at speed.

Rocks start turning up around the hundred-metre mark, and the hill thickens with depth: the slope is generated in 32-metre bands, which carry six obstacles each at the top and climb to sixteen by about 1900 metres, where the density plateaus. Nothing is ever placed within 4.5 metres of anything else in the same band, which is what stops the generator producing a wall you cannot get through. If you crash, it was avoidable.

The yeti

At 2000 metres something comes over the ridge behind you, and the game stops being about the trees. The yeti travels at 27.5 metres per second — faster than your fastest tuck — so it cannot be outrun. It can only be delayed.

Tucking closes the gap at about 1.5 metres per second, which buys you roughly ten seconds. Cruising closes it at nearly ten metres per second, which buys you under two. So the arrival of the yeti inverts the game's central tradeoff: for the whole run up to that point, turning was a tax you paid for safety, and now standing off the tuck is a much larger tax paid for the same thing. The trees do not stop being dangerous just because something worse has appeared.

It tracks sideways more slowly than it closes from behind, so cutting hard across the slope buys a little time — at the cost of the speed you need. And it is not skiing: it goes through the trees, not around them. Nor can you jump it. Ramps are a pass through whatever is on the ground, and the yeti is not on the ground in any sense that matters.

There is no way to survive it, and that is deliberate. Every run ends; the yeti just decides how. Reaching it at all takes a good run, and the distance you were at when it caught you is the real measure of one.

Sound

The wind rises with your speed, so a tuck is audible before it is visible on the speed readout. Ramps, landings, moguls, crashes and the yeti each have their own sound. Nothing plays until you start a run — browsers only permit audio after a deliberate action, and pressing Start is that action. Sound on under the slope turns it off, and your choice is remembered.

There are no audio files. Every sound is generated in your browser from oscillators and noise as it plays, which means the game downloads no audio at all, works offline like the rest of the site, and adds nothing to what your device has to store.

Scoring

One point per metre descended, plus two points for every metre you cover in the air. Jumps are therefore worth more the faster you are going when you hit the ramp — the air time is fixed, so your speed decides how far it carries you. A tucked take-off is worth substantially more than a cautious one. Your best score is kept in your browser and never leaves it.

Slopes are seeded, and the seed is in the link

Every slope is generated from a short seed shown under the canvas, and the same seed always produces exactly the same hill — same trees, same ramps, same everything. The seed lives in the page address, so copying the URL and sending it to someone hands them your exact run to try. Restart slope gives you another go at the hill you are on; New slope rolls a fresh one.

This is not a leaderboard and there is no server involved. The seed is the whole mechanism: two people on the same seed are skiing the same mountain, and the only thing that differs is the line they take down it.

Technique

Three things separate a 500-metre run from a 2000-metre one. First, stay near the middle. The slope edges are walls — you cannot ski off the side — but being pinned against one halves your options when something appears ahead. Second, tuck on the gaps, not on the trees: the extra speed is worth most where you can see clear snow, and worst where you might need to turn. Third, take the ramps. Air time is free distance, free points and a free pass through whatever is underneath you.

The game runs entirely in your browser, works offline once the page has loaded, and stores nothing about you anywhere. It honours your system's reduced-motion setting by pinning the scattered snow tufts and bare patches in place, so the background stops streaming past as a texture.

About the genre

The endless downhill skier is one of the oldest shapes in computer games, and the best known example is SkiFree, written by Chris Pirih in 1991 and still fondly remembered for the creature that eventually catches everybody. The unwinnable pursuit is the idea that game contributed to the genre, and Ski Slalom's yeti is our own take on it — our own code, our own artwork, our own physics. No assets or code from any earlier game are used here.