Sling — the daily physics gauntlet
How good is your feel for motion? Sling is a free browser physics-intuition game: five quick rounds, the same for everyone each day, each one a prediction about how things move — a flying ball, a cut string, a gear chain, a bounce, a collision. You commit your call first, then the true motion plays back so you see exactly how right you were. No signup — a full daily takes about a minute.
The five rounds
| ARC | A cannon fires — you see just the first blink of the launch, looping. Tap the spot on the ground where the ball will come down, then lock it in and watch the full arc fly. Close counts: partial credit scales with your miss, and the tolerance is paced for eyeballing a real trajectory — a near call scores well. |
| SPIN | A ball whirls on a string. The string gets cut exactly at the gold notch — tap the point on the outer ring where the ball will cross. A cut string flies straight, in whatever direction it was moving at the cut — it doesn't keep curving, and it doesn't shoot straight out from the middle. If your mark drifts on around the ring with the spin, Sling says so mid-round — and asks once before letting you lock a mark that's still riding the curve. |
| GEARS | A chain of meshing gears — the driver turns with the arrow. Call which way the last gear turns: CW or CCW. Every meshing pair flips direction; a belt link keeps it. This is the one timed round — a quick confident call scores higher — and after you lock, the whole chain turns so you can check every tooth. The clock is paced to the chain: longer gear trains and belt links get more thinking time. |
| BOUNCE | A ball flies at a tilted pad — the path in is drawn for you. One perfectly elastic bounce: angle in equals angle out. Tap where it lands on the ground afterwards, then watch the carom. The pad is never the finish: if your flag sits right under the strike point, the game reminds you the bounce carries the ball onward. |
| MEET | Two dots glide at steady speeds — you get a short preview of their motion, twice, and their speed arrows stay drawn. Tap where the two will collide. Steady means steady: no speeding up, no curving. |
Scoring
Every round scores your feel for motion from 0 to 100 — full marks for dead-on, partial credit for close. Your daily result is the average of the five rounds, plus a five-square trail (🟩 called it · 🟨 close · 🟥 way off) you can copy and send as a challenge — the link carries your score, so a friend who opens it is dared to out-call you. Come back tomorrow for a fresh gauntlet and build a daily streak — beat yesterday's score to sharpen it, and if you miss a day your personal best is saved and waiting. The menu shows your last seven days as a chain of squares — each finished gauntlet fills one, and today's pulses until you play. After you finish, the results screen shows today's rivals — how many players ran the gauntlet in the last 24 hours, the best score among them, and where yours ranks. Rivals are always anonymous: a count and a score, never names or accounts.
Controls
| Adjust | Tap or drag (mouse or finger) — tap the ground, the ring or the open field to place your marker; tap the CW / CCW zones on the gear round. Desktop: arrow keys fine-tune. |
| Answer | The LOCK IN button commits your call — only GEARS is on the clock, every other round lets you take your time. |
| Start a round | Each round waits for you — nothing starts until you're ready. |
Modes
Daily gauntlet: 5 seeded rounds — launches, strings, gear chains, bounces and collisions identical for every player worldwide that day. One attempt each. Mid-gauntlet progress is saved if you get interrupted. The very first time the gear chain fools you, you get one more look at a fresh chain — after that they all count.
Practice — the physics trainer: endless rounds, your way. Pick all five mixed or drill a single skill — arc, spin, gears, bounce or meet. Every drill climbs a 12-level difficulty ladder: score green and the next round gets harder — longer gear chains, tighter tolerances — score red and it steps back down. Your current and best level per skill live in the picker: how high can you climb? Sling also keeps a lifetime accuracy average per skill (from both daily and practice rounds, stored only in your browser), so the picker doubles as your physics profile: it shows your average and level for each skill and flags your weakest round from today's gauntlet. Every round you finish — daily or practice — also earns XP equal to its score: climb a 12-rank ladder from wild guess through trajector and ballistician up to dead eye. Your rank only ever goes up, and it lives in your browser — no account needed.
Tips
- Arc: steeper launches hang longer but land shorter than they feel. Watch how fast the ghost dots climb — speed is half the answer.
- Spin: freeze the ball at the notch in your mind and ask "which way is it moving right now?" — that straight line is the whole answer.
- Gears: don't simulate every tooth — count the meshes. Odd number of meshes flips the driver's direction, even keeps it. Belts don't count.
- Bounce: mirror the incoming path across the pad, like a billiard shot. The pad's tilt matters more than it looks.
- Meet: the collision sits closer to the slower dot's start than your eye wants — follow the arrows, not the midpoint.
Sling is a game, not a physics exam — it measures the intuition everyone builds by throwing, catching and watching things move, and every round shows you the truth after you call it.
FAQ
Is it free? Do I need an account? Free, no account, no install needed. It runs in any modern browser, on phones and school Chromebooks alike. If you'd like the daily one tap away, you can add Sling to your home screen from your browser's menu. No download, no store, it's the same game in an app-shaped wrapper.
Is it the same puzzle for everyone? Yes — the daily gauntlet is seeded by the date, so your 73 and your friend's 88 came from identical launches and gear chains.
Does it work in my language? Practically yes — the rounds are balls, gears and arrows, not words.
Who made this? Sling is an original game by Yuki Andersen. More free games: Gauge, Glimpse, Tempo, Prism, Keel, Scout, Weft, Helm, Wordpull, Floe, Ballast, Well Duel, Well Putt, Wellspring.
