Zerdly

Micro Kart Sprint

Compact kart racing with approachable drift-to-boost handling and purely original track hazards. 8 circuits, 5 modes including a championship and a daily track.

Pick a race

Circuit

How a race works

Driving

  • ↑ or W accelerates, ↓ or S brakes, ←→ steer.
  • Hold Space through a corner to drift. On a phone, the wide ≈ button does the same thing.
  • P pauses, R restarts.

Drifting, and what it is worth

  • The drift only engages when the kart is actually turning and travelling at least 25 km/h. Holding the key on a straight does nothing at all.
  • Charge builds once the kart is sliding by about 6° — the bar fills and the kart visibly points away from where it is going. It is worth something after 0.35s of full slide (the mark on the bar) and is full after 2.2s. Holding on past that earns nothing more.
  • Letting go cashes the charge as a boost of at most 2.8s. Two drifts in quick succession do not stack past that cap. One press is one drift — hold the key and the slide ends and pays out by itself once the charge is full, so there is no way to lose time by hanging on.
  • Drifting costs a little cornering grip and takes a wider line, so a slide is slower through the turn and faster afterwards. Drift almost every corner. It is worth most where a tight corner opens onto a medium straight, and least on a very long one — there, an unboosted kart reaches the same top speed before the end anyway.

The circuit

  • Checkpoints must be crossed in order, so cutting across the infield does not shorten a lap.
  • Beyond the white line is run-off: much less grip and a lot more drag. Nothing stops you going there — it simply costs time.
  • Painted stretches change the handling and nothing else: Damp patch, Rumble strip, Dust drift.

Modes

  • Quick Race — Three laps against seven rivals. One race, one result. 7 rivals, 3 laps.
  • Cup Series — Four tracks in order. Points carry between races and the cup is won on the total, not on the last one. 7 rivals, 3 laps.
  • Time Trial — No rivals. Your own best lap drives alongside you as a ghost, and restart is one key away. 3 laps, alone.
  • Elimination — Last kart on the road is out every thirty seconds. Survive. 7 rivals, 12 laps.
  • Daily Track — One generated circuit for everybody, changing at midnight UTC. Same seed, same track. 7 rivals, 3 laps.

Rivals

  • Rivals drive the same kart you do, with the same grip, the same top speed and the same drift rules. A harder rival brakes later, wanders less and judges its drifts better — it is never given a bigger engine and never catches up because you are ahead.

Your data

  • Best laps, ghosts, championship progress and settings are stored on this device only. Nothing is sent anywhere, and clearing this game leaves the rest of Zerdly alone.

Drifting is faster, and we measured it

A slide costs you through the corner and pays you on the way out. Dropping the kart sideways gives up a little grip, so you carry slightly less speed round the turn — and the boost you cash at the exit more than covers it.

That is not a claim, it is a number. Bots driving identical karts with nine different drift policies were raced over all 8 circuits: the best policy beats never drifting by about 2.6% of lap time.

And it is meant to be easy to get most of. Drifting every corner rather than only the best ones costs 2.1%. The skill is not where you drift — it is when you let go.

How to play

Arrows or WASD steer, accelerate and brake. Hold space through a corner to drift; on a phone the wide button in the lower corner does the same. P pauses and R restarts.

The charge bar fills while the kart is genuinely sliding. The mark on it is the point where letting go starts paying — about 0.35 seconds of full slide — and the bar is full after 2.2. Release as the corner opens, and the boost runs down the straight rather than into the next apex.

A kart tops out at about 83 km/h, or 134 km/h on boost, and holds roughly 1.38 g in a corner before the tyres give up.

The track hazards are the road, not objects

There is nothing to pick up and nothing to dodge. The painted stretches are surfaces: a damp patch takes grip away without slowing you, a rumble strip scrubs speed, and blown grit off the infield costs a little of both. They are handled entirely in the physics, so a hazard changes how the kart behaves rather than firing an event at you.

Beyond the white line is run-off. Nothing stops you going there — it simply has far less grip and far more drag, so running wide costs time all by itself without any rule having to punish you.

Modes

Quick Race
Three laps against seven rivals. One race, one result. 7 rivals over 3 laps.
Cup Series
Four tracks in order. Points carry between races and the cup is won on the total, not on the last one. 7 rivals over 3 laps.
Time Trial
No rivals. Your own best lap drives alongside you as a ghost, and restart is one key away. 3 laps, alone.
Elimination
Last kart on the road is out every thirty seconds. Survive. 7 rivals over 12 laps.
Daily Track
One generated circuit for everybody, changing at midnight UTC. Same seed, same track. 7 rivals over 3 laps.

Tips

  • Drift almost everything. Picking your corners is worth about two per cent; not drifting at all costs you two and a half, and nearly seven on the circuits that suit it.
  • Let go as the corner opens, not at the apex and not on the straight. Both of those cost two to six per cent.
  • A corner followed by a long straight is the one worth being careful about — that is where a full boost has somewhere to go.
  • Running wide is slower than lifting. The run-off has less than half the grip of the road.

Privacy and local play

Everything runs in your browser. There is no sign-in, no server and no gameplay API: your best laps, ghosts, championship progress and settings are stored on this device only, under keys belonging to this game alone, and clearing them does not touch anything else on Zerdly.

Questions

Is drifting actually faster, or does it just look good?
Faster, and it was measured rather than assumed. Bots with identical karts and nine different drift policies were raced over the eight circuits: the best drifting policy beats never drifting by about 2.6% of lap time, and by as much as 7% on the circuits that suit it. A slide costs a little cornering grip, so it is slower through the turn — the boost you cash on the way out is what more than pays it back.
Do I have to be precise about it?
No, and that is the design. In the same measurement, simply drifting every corner rather than picking the best ones costs only 2.1%. The charge also stops building once it is full, so holding on too long wastes nothing but a little grip. And holding the button down is not a trap: one press gives you one drift, which ends and cashes itself as soon as the charge is full.
Why does the drift sometimes do nothing?
Because the charge is gated on the kart actually sliding, not on the key being held. You need to be above 25 km/h and genuinely turning; below about 6 degrees of slide, nothing accrues. Holding the button down a straight is free and worthless.
How long is a boost?
At most 2.8 seconds, always. A release starts paying after 0.35 seconds of full slide — that is where the mark on the charge bar sits — and the charge is full after 2.2 seconds. Two drifts in quick succession take the longer of the two rather than adding up, so there is no way to stack past the cap.
What are the coloured stretches of road?
Surfaces, and they change the handling and nothing else. A damp patch has much less grip but no extra drag, a rumble strip scrubs speed, and blown grit costs some of both. There are no items, no pickups and nothing lying on the road to collect or dodge.
Can the rivals cheat?
No. Rival karts run through exactly the same physics as yours, with the same grip, the same acceleration and the same drift rules — the only thing a difficulty setting changes is what they do with the wheel: how late they brake, how much their line wanders, and how well they judge which corners are worth drifting. Nothing about being ahead or behind changes their speed.
What stops me cutting a corner?
Two separate rules, because one is not enough. Checkpoints have to be crossed in order, so no shortcut can shorten a lap; and the edges of the circuit are real geometry, so running wide puts you on run-off with much less grip and a lot more drag. Ordered checkpoints alone can still let a lap stray a long way across the infield, which is why the road has an edge as well.
Is the Daily the same for everyone?
Yes. The circuit is generated from the UTC date and nothing else, so two people on opposite sides of the world race the same track on the same day. Your best result for the day is the one kept.
How does the Cup work?
Four circuits in a fixed order — 4 rounds — with points carried between them. The points reward winning clearly but not ruinously, so a bad round is survivable and the championship is usually still alive going into the last race. Your progress is saved on this device, so you can come back to a cup mid-way.
Does reduced motion make it easier?
No. It swaps the chasing camera for a steady view of the whole circuit and calms the effects; it changes no rule, no timing and no score. The route also follows your operating system's reduced-motion setting automatically.
Why is there no leaderboard?
There is no server and no account, so there is nobody to compare you with. Your best laps, ghosts, championship progress and settings live in this browser and nowhere else.

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