🚵 DOWNHILL MAYHEM

A free, browser-playable, fan-made tribute to Downhill Domination (PS2, 2003) — one long point-to-point race down a mountain against 5 AI rivals, with mid-air tricks that charge a boost meter and fists (and boots) that settle position disputes.

▶ PLAY NOW — free, in your browser

Fan-made tribute. Not affiliated with Sony or the original developers. No original game assets are used: every model is built from Three.js primitives, every texture is canvas-generated, and every sound is synthesized at runtime with the Web Audio API.

Play it

• In your browser (desktop or phone): pranshuparmar.github.io/downhill-mayhem
• On itch.io: pranshuparmar.itch.io/downhill-mayhem
• Locally: just double-click index.html. Fully offline — nothing is fetched from anywhere, ever.

📱 On phones and tablets, touch controls appear automatically: steer and brake with the left thumb; jump, tricks, punch/kick and boost with the right. Pedalling is automatic, boost is tap-to-toggle, and the game asks you to rotate to landscape (or just tap that screen to go fullscreen — it auto-rotates). The top button row covers the CRT filter (📺), PB ghost (👻), mute, restart, home and fullscreen. Switch away mid-race and the game pauses; tap to drop back in. 🎮 Controllers work too — plug in a DualShock/Xbox pad and press ✕.

The whole game is a single self-contained index.html — three.js included inside it — no build step, no npm, no server; the gameplay makes no network calls at all (the hosted build counts anonymous, cookieless visits and milestones — see Analytics).

Controls

Input	Action
↑ / W	Pedal
↓ / S	Brake — or Backflip while airborne
← → / A D	Steer — hold a hard turn at speed to break into a slide
Space	Bunny hop — hop right at a ramp lip for bonus air
Z X C	Tricks while airborne: No Hander / Superman / Heel Clicker
Shift	Boost (drains the meter)
E	Punch a nearby rider off their bike — works mid-air too
F	Kick — also mid-air; landed hits pay boost, extra while airborne or boosting
R	Restart the race
M	Mute audio (music and all)
T	Toggle the CRT scanline/vignette filter
G	Toggle the ghost of your best run
H	Show/hide the control-hint line (it auto-fades a few seconds into each race)
Esc / Backspace	Back to the title screen — pick your mountain (←/→), difficulty (↑/↓) or today's DAILY (D) there (the results screen has a ⌂ button too). In fullscreen use Backspace or ⌂: browsers reserve Esc for exiting fullscreen
⛶ (top-right)	Fullscreen on/off — on desktop and mobile alike
🎮 Controller	DualShock/Xbox or any standard pad: stick steer · R2 pedal · L2 brake (backflip in air) · R1 boost · ✕ start/hop · □ punch · ○ kick · L1/△/R3 tricks

How it plays: the mountain does most of the accelerating — pedal out of the gate and out of slow corners, brake before the sweepers, and hit the wooden kickers for airtime. Start a trick in the air and land after its bar fills to bank boost meter; land mid-trick and you eat dirt — though a pose trick that's nearly done can be saved: no payout, a wobble, but you keep the bike under you. The backflip is stricter, though — it's a full rotation, so land it before you've come most of the way around and you land on your head, no save. The finish line trumps all of it, though: cross it and your result locks the instant you're across — airborne or grounded, trick landed or blown — so a flip you botch right at the banner still counts you home. Chain tricks in one jump for bonus meter, and clean riding trickles meter in on its own — crashing dumps most of it. Monster airs land heavy but rideable (air drag caps your fall speed) — what actually bites is casing an upslope face at speed. The groomed line is fastest, but the whole hillside is rideable: rollers, dirt patches and slalom trees open up alternate lines. Corners throw you outward — hold the turn and counter-steer, or commit to the slide. Rivals shove, punch and kick when you ride close — swing first (E/F), and land a mid-air kick for an AIR STRIKE bonus. They mix it up, too: a rival throws jabs and boots at random, and the hit tells you which caught you (a KICKED! reads and lands harder than a PUNCHED!). They ride like people, too: they throw tricks off the kickers for their own boost, and they spend the meter with a plan instead of dribbling it away — a quick early squeeze to finish a pass or clear a ramp lip (a boosted launch buys the air for a bigger trick), a bigger chest saved for a straight, and a near-full bar spent rather than wasted. Early or full, it's a judgement call, not a fixed wait. The pack races for keeps: rivals roll off the gate with boost already banked, burn it to close any gap, hound a clean leader all the way down, and empty the tank over the final stretch — no lead is safe. Fall off the back and a couple of backmarkers will dawdle within sight to keep the race alive — but the leaders never wait, and if you're crash-looping they'll all leave you to the mountain. Every race deals five rivals from a twenty-strong roster with fresh names and jersey colours, so the field never feels like the same faces twice.

Four mountains, three difficulties: pick both on the title screen — ←/→ cycles the three hand-built mountains, ↑/↓ the difficulty (tap the rows on touch), each flick clunking like a cassette-deck button. The DAILY gets its own showcase row below the selectors so it never hides as a fourth name in the cycle — hit it (D, or tap) to drop onto today's mountain.

• CLASSIC — the canonical course: alpine frost into warm canyon, the all-rounder.
• TIMBERLINE — dense forest, tight rhythm, slalom tree weaves everywhere.
• ROCKGARDEN — wide, steep and littered with rock gardens: clusters of pale boulders squatting on the line. They hide lower than trees and hit just as hard — read them early, pick a side, or bunny-hop straight through. Even the AI checks its speed and threads a lane (avengers don't).
• DAILY — a brand-new mountain from today's UTC date, identical for every player in the world, with its own framed showcase row on the title (press D or tap it). Every daily rolls its own personality: twist, rhythm, steepness, drops, kickers, forestation, biome split — and some days, rocks.

Difficulties: CHILL (a pack you can outride cleanly), MAYHEM (the game as designed — rivals cruise above your clean ceiling; spend boost, tricks, draft or fists), and BRUTAL (they're ~15% faster than your clean ceiling, roll off the gate loaded with boost, and swing constantly — and a BRUTAL grudge does not expire: deck a rival and they hunt you for the rest of the race, closing faster than physics ought to allow. Crucially, a BRUTAL avenger keeps racing while it hunts — it won't park to wait for payback the way a CHILL or MAYHEM grudge does, so knocking rivals down no longer thins the field; they punish you and stay in the race. Winnable, barely, and never cleanly. Fall off the back on BRUTAL and nobody dawdles for you — you're alone with the mountain). Difficulty also scales the revenge machine itself: how long a decked rival hunts you, how fast they run you down, and how little warning their swing gives. Personal bests and ghosts are tracked per mountain per difficulty; everything recorded before difficulties existed counts as MAYHEM.

Chasing the mountain: the game remembers your best time per mountain (stored locally in your browser — still no accounts, nothing leaves your machine). Beat it for the NEW PERSONAL BEST fanfare. The HUD shows the live gap to the rider ahead, every overtake pops on screen, and the results screen ends with a one-line recap of how your race actually went plus your run's stats — top speed, biggest air, tricks, best combo, riders decked. Hit 📸 SHARE RESULT CARD for a shot of your rider on the mountain with your grade stamped over it and your time — generated locally (like everything else) and handed to your device's share sheet, or saved as a PNG where sharing isn't available. The card carries your challenge link as text, so anyone who sees the image can type it in and race your exact mountain and time — and if the run was a challenge, it stamps your CHALLENGE BEATEN / MISSED verdict right on the card too, so a won challenge reads as a win at a glance, not as any other race. Restarts use a shortened countdown after the first race, and Esc returns to the title screen.

Challenge your friends: after any race, hit CHALLENGE A FRIEND on the results screen — it copies a link that carries the exact mountain, your time and the difficulty you set it on. Anyone opening it starts the game on that same mountain and difficulty, sees your time as a HUD target, and gets an unmissable CHALLENGE BEATEN (green) or CHALLENGE MISSED (red) badge on the results screen — which, like the result card, always names the mountain and difficulty you raced. Switch mountain or difficulty and the challenge politely waits (the title says so) until you switch back — never blocked, just not competing. Old links from before difficulties existed count as MAYHEM. The whole challenge lives in the link; there is no server and no account.

The rest of the arsenal: the title screen is a live broadcast — an AI-only race runs behind the menu with spectator camera cuts, arcade attract-mode style, until you press start. Your best run rides with you as a translucent ghost (G or the 👻 button toggles it). A synthesized drum-and-bass loop kicks in at GO — the wind ducks out of its way — and intensifies in the final stretch. Every mountain has its own groove: CLASSIC's canonical 136 BPM two-step, TIMBERLINE's slower broken-beat minor stomp, ROCKGARDEN's 148 BPM sawtooth assault — and each daily rolls its own tempo, bass line and drum pattern from the seed. The mountain talks back too: trees answer with a hollow wooden knock, rock gardens with a stony crack, a boot lands deeper than a fist, and a plain crash is just you and the dirt. Tuck in behind a rider to slipstream, then swing. Butter a landing on the downslope for a CLEAN bonus. The descent itself changes as you drop — frosty alpine up top, pine forest in the middle, warm canyon at the bottom. Switch apps or tabs mid-race and the game pauses itself — you come back to a PAUSED screen and drop back in with any key, tap or pad button, never into a mountain that kept moving without you. Finish within half a second of anyone and you get the PHOTO FINISH freeze. Every race ends with a graded rank stamp, F to A+ with a one-word verdict: your finishing spot sets the band (a plain win is an A — LEGENDARY takes style), and tricks, knockdowns and PBs fill it. And any rival you deck drops the race plan and hunts you — smouldering red, faster than any racer has a right to be, waiting for you if they must — until they've knocked you down and honour is settled. Then they go back to racing.

Tech notes

• Everything lives in one HTML file — including its only dependency, three.js r128 (MIT, see THREE.LICENSE), inlined directly. The file works from file://, from any static host, and keeps working even if every CDN on Earth disappears.
• Seeded procedural courses (~2.3 km, ~16% average grade) — three hand-tuned mountains plus a fresh date-seeded Daily, each deterministic so everyone rides the same hill: sweeping turns, steep chutes, step-down drops, wooden kickers, rock gardens, and a broad rolling hillside around the racing line.
• Riders simulate in track space (distance-along-course, lateral offset, height) and are converted to world space for rendering; terrain, physics and scenery all share one analytic ground function.
• PS2-era look on purpose: chunky flat-shaded low-poly terrain with vertex colours, aggressive distance fog, instanced pine trees and boulders, blob shadows, and an optional CRT scanline overlay.
• Zero accounts, zero ads, zero cookies, zero tracking of you. Your best times live in localStorage on your own machine and nothing about your play ever leaves it. See Analytics for the one request the published site makes.

Analytics

The published site counts visits and a handful of anonymous milestones — a race started (and on which mountain and difficulty), a race finished, a win, a personal best, a top grade, a photo finish, first boost, first trick, a three-trick combo, a rival decked, a payback taken, a crash, a challenge link arrived at, copied, beaten or missed, and a result card saved or shared — via GoatCounter: cookieless, no identifier stored in the browser, and nothing about you kept. It is a thin wrapper that silently no-ops when the counter is blocked or unavailable, so the game never depends on it, and each event counts at most once per page load — the interesting figures are per-visit ratios (started vs finished vs won), not repeat presses.

It is skipped entirely on file://, localhost and LAN addresses, so a local or offline copy makes no network request at all and local play stays out of the numbers. Nothing about this appears in the game itself; the milestones a page load would count are listed in window.TRACKED if you want to audit them.