How to play

1. The idea

Something has already happened: the vase is broken, the ball is in the basket, the cat has run off. All you have is a photo of the aftermath.

Your job is to rebuild the hidden mechanism that caused it: place parts (ramps, trampolines, catapults…) so that after the run everything in the room ends up exactly where it is in the photo.

It is all real physics: weight, bounces, friction, slopes. The same mechanism always gives the same result.

2. A case: the photo and the case file

• The photo (top right) shows how everything looked at the end. The numbers on it are the evidence. Tap the photo to enlarge it.
• The case file tells you the place, the time, the conditions (a place's own physics), what is fragile and how much, which parts you have and how many, the star rules and the list of evidence.
• The evidence is what matters: “The vase is broken on the floor”, “The ball is in the basket”, “The cat ran off to the right”. This is what is checked after a run.
• Some cases have a second photo, “after 2.5 s”: where the ball was at that moment. A chapter's final case has three photos.
• A witness tells the order of events: “First the cat woke up, then the vase broke”.

• Security camera — some cases have a “Camera” frame on the blueprint and footage in the case file: what could be seen in that corner of the room. The ball must cross the frame at the same place and time.
• Marks — dark marks on the photo and crosses on the blueprint: there the ball struck a wall, the floor or furniture hard. Your mechanism must send the ball through every mark.

3. Solving a case

1. Study the photo and the evidence: what broke, what fell, where the cat ran.
2. Press “TO THE BLUEPRINT”: the plan of the room “before” opens, showing where everything stood at the start.
3. Drag parts from the tray onto the blueprint, turn them, place them the way you think it happened.
4. Press “RUN”: the physics plays for 7 seconds. A dotted line shows the ball's path.
5. The result: how closely you match the photo, overall and for each piece of evidence. A blue dotted outline shows where a thing should have ended up, a red circle shows where yours is.
6. “TRY AGAIN”: adjust the mechanism and run again. As many tries as you like.

If you are really stuck, “Show what really happened” plays the real mechanism. The case then counts for opening the next one, and you can still earn stars with your own run.

4. Controls

• Add a part: drag it from the tray onto the blueprint (or tap it in the tray).
• Move: drag the part on the blueprint.
• Move precisely: the arrows next to the selected part (hold to keep moving) or the ←↑→↓ keys, with Shift by 10.
• Turn: the round red handle, the mouse wheel, keys Q / E; on a phone, two fingers or the slider below.
• Remove: the “Remove” button or the Delete key.
• Conveyor and pulley: the direction button turns the belt round or swaps the pulley's sides.
• The timeline under the scene: pause and play (space bar), rewind and fast-forward to any moment of the run.
• Full screen: the button in the header or the F key.

5. Parts

Each case has its own kit — see “Kit” in the case file. Here is what each part does:

• Ramp — The ball rolls down it. The angle sets the slope and the direction.
• Trampoline — Throws whatever falls on it up along the yellow arrow. Tilt the trampoline to send the ball sideways.
• Stopper — A fixed wall: the ball and other things hit it and bounce off or stop.
• Catapult — When the ball lands on the raised end, the weight on the other end flies along the yellow arrow. The tilt decides which end is raised.
• Cushion — Soaks up the fall: what lands on it stays there, and a vase on it does not break.
• Fan — Blows along the arrow all the time: it carries away the light mug and weights and only nudges the heavy ball. The angle sets the direction.
• Pendulum — At 0° it hangs and waits to be pushed. Tilt it and it lets go at the start and hits whatever is in its way.
• Pulley — When a load drops into the cup, the cup goes down and the platform on the other rope shoots up three times as fast, throwing the weight. At the bottom the cup tips over. “Flip” swaps the sides.
• Conveyor — The belt carries whatever lands on it along the arrow. “Direction” reverses the belt, the angle sets its tilt.

6. The ball, the things and the cat

• The ball weighs about 8 kg. Sometimes it is a tennis ball or a cast-iron one instead; the case file says so:
• The fragile thing (a vase, a glass, an aquarium…) breaks on impact; how strong it is is shown in the “Fragility” line. Sometimes it is an egg, which breaks from almost any fall.
• The mug and other light things fall, roll, and are blown away by the fan. Sometimes the mug is a cube (it slides) or a can (it rolls).
• The cat is asleep. It wakes up when something hits it or makes a loud noise nearby (the crash of a breaking vase) and runs away from the noise. The cat weighs about 5.5 kg: a trampoline throws it, a belt carries it, it runs up a ramp, and it is afraid of the fan. The evidence says where it ran.
• The ceiling lamp in the kitchen and the living room hangs on a cord: the ball can set it swinging, and the lamp can knock something off.
• The furniture is real: the ball bounces off chairs, the fridge, the car; things stand on it and fall off it.

• Tennis ball — bounces high, a fan blows it away, too light to fire a catapult
• Cast-iron ball — hardly bounces, a fan cannot move it, a trampoline throws it only a little, and it hits hard

7. Each place's physics

Most places have physics of their own — the case file shows it under “Conditions”. Here they all are:

• Speeding up — the train is pulling away, so everything loose drifts a little to the left (Train compartment)
• Braking — the train is braking, so everything loose drifts a little to the right (Train compartment)
• Emergency brake — a second in, the train brakes hard: for a second and a half everything loose is thrown to the right (Train compartment)
• Air pocket — about 1.5 s in, the plane drops and for two seconds everything is almost weightless (Plane cabin)
• Dive — a second in, the plane drops hard: for four seconds everything is almost weightless, then heavier than usual while it levels out (Plane cabin)
• Take-off — half a second in, the plane lifts its nose: the floor tilts and everything loose slides to the right, towards the tail (Plane cabin)
• Landing approach — half a second in, the plane lowers its nose to land: the floor tilts and everything loose slides to the left (Plane cabin)
• Weightlessness — nothing weighs anything here: the ball flies straight and bounces off whatever it meets, and everything loose floats (Space station)
• Swell — the ship rolls on the swell: “down” slowly swings left and right, so things drift one way, then the other (Ship's cabin)
• Storm — a storm: the ship rolls hard and fast, and the deck heaves, so things are heavier and lighter by turns (Ship's cabin)
• Going up — the lift starts up: for a second everything is heavier, and as it slows down before the floor, lighter (Freight lift)
• Going down — the lift starts down: for a second everything is lighter, and as it brakes at the floor, heavier (Freight lift)
• Cable snapped — a second in, the cable snaps: two and a half seconds of falling, almost weightless, then the safety brakes grab hard (Freight lift)
• Ice — the floor is ice: whatever lands on it keeps sliding, nothing stops it but a wall or furniture (Ice rink)
• Water — in the pool everything slows down; light things float up, the ball sinks slowly, a heavy one goes straight to the bottom (Swimming pool)
• Moon gravity — on the Moon everything weighs a sixth of what it does on Earth: things fall slowly and fly far (Moon base)
• Diving — half a second in, the submarine dives: the deck tilts nose down and everything loose slides to the left (Submarine)
• Surfacing — half a second in, the submarine rises: the deck tilts nose up and everything loose slides to the right (Submarine)
• Mars gravity — on Mars everything weighs a little over a third of what it does on Earth, and dust-storm gusts push everything sideways now and then (Mars base)
• Turning floor — the carousel floor turns: everything loose is thrown outwards, the harder the further it is from the middle (Carousel pavilion)
• Drifting — the balloon basket sways slowly in the wind: “down” leans a little one way, then the other (Balloon basket)
• Stop and go — the bus pulls away, brakes, then pulls away again: everything loose slides back, forwards and back (City bus)
• Wet floor — the wet tiles are nearly as slippery as ice, and there is a bath full of water (Bathroom)
• Springy mats — the floor is springy gym mats: whatever lands on it bounces back up (Gym)
• Electromagnet — the electromagnet on the wall pulls the ball (and a tin can) towards it, harder the closer it gets (Chemistry lab)
• Trapdoor — 2.5 s in, the trapdoor in the stage drops open: whatever stands on it falls through (Theatre stage)

8. Score and stars

• Each piece of evidence gets a percentage: the closer the thing is to its place in the photo, the higher. If it is broken in the photo but whole in your run (or the other way round), that evidence scores almost nothing. For the cat, whether it woke up matters too.
• The total is the average over all the evidence. 90% or more and the case is solved.
• ★ first star: solved (90%+).
• ★ second star: and no more parts than the investigation used.
• ★ third star: and an accuracy of 97%+.

Your best result and stars are kept; you can always try again.

9. Badges and awards

• ◆ Your own version: as many parts as the investigation, 97%+, but a clearly different mechanism.
• ✦ Genius: the case solved (90%+) with fewer parts than the investigation used.

After a solved run the stage shows the “Awards for this case” card: what this run earned, what you had before, and why something is missing.

10. Kinds of cases

• An ordinary case: a photo and evidence; you find the mechanism.
• “What went wrong” (case 2 of a place): the investigation's mechanism is already on the blueprint, but one part is wrong. Find it and put it right.
• “Two targets” (case 9 in some places): two things at opposite ends of the room were hit; you need a chain, one throw will not do.
• A chapter's final (the last case of a place): several hidden parts, a chain of events and three photos: after 2 s, after 4 s and at the end.

• “Prevent it” (case 6 of a place): the mechanism is known and fixed on the blueprint, and the photo shows what it did. Add one part so that nothing breaks, while the ball still touches every part of the mechanism.

11. Chapters and places

• Each chapter is one place: a kitchen, an office, a garage, a train, Mars, a theatre… 30 in all.
• Chapters 1 and 2 (Kitchen and Office) teach the game: each case brings one new part.
• Each place has 10 cases, made for you alone — other players get different ones.
• Cases inside a chapter open one by one: the next opens when the previous is solved or its solution was viewed.
• The next chapter opens after 7 cases of the previous one. Another way in: solve a catalog level in a closed place, and that place's chapter opens at once.

• It gets harder as you go. The dots on a place's card show its difficulty from 1 to 5: later chapters have fewer easy cases, their hard cases hide three parts instead of two, and there are more closed zones, more evidence and more unusual balls.

12. Daily case and random cases

• The daily case is the same for everyone and new every day. Keep a streak, and see the daily ranking: fewer tries and fewer parts rank higher.
• New case: “Easy”, “Medium”, “Hard” gives you a random case of that difficulty, as many as you like.

13. Level builder

• Pick a place and its blueprint opens. Drag the ball, the things, the cat, the basket and the furniture, hide a mechanism made of parts from the tray, and on the right choose the title, the fragile thing, the ball and the time of day.
• “RUN” shows the photo your level will have. “Save” checks the level: the mechanism is not empty, parts do not overlap each other or the furniture, and the case does not solve itself without the mechanism. Parts that change nothing are removed.
• “Link”: the whole level fits in a link, so a friend opens exactly your level.
• Only places you have opened are available in the builder.

14. Catalog

• Levels published by players: “Best this week”, “Top”, “New”, and a filter by place.
• To publish your own level or to like one, sign in. Keep the title clean.
• ⚑ on a card: report a level (offensive title, or it does not work).
• Solve a level in a place you have not opened yet, and both that place's chapter and the place in your builder open.

15. Account, progress, links

• Your progress and stars are kept in this browser. Signing in (Google, no password or e-mail) brings them to all your devices.
• You can share a link to a case or to your solution. “Save video” records a clip: the photo → the run → the score.
• You can install the game on your phone: “Add to Home Screen” in the browser menu.

16. Tips

• Start with the most striking evidence: what broke and where. That is almost always the end of the chain.
• Watch the ball's dotted path and the red circles after a run — they tell you which way to move things.
• Move parts a little at a time: a few centimetres change everything.
• Mind the place's physics: a ship rolls, everything is lighter on Mars, in zero gravity the ball flies in a straight line.
• The cat ran right? Then the noise came from the left.
• Stuck? Look at the solution. No shame in it: that is how the next case opens.