Concept · 5 screens

Contraption

A browser puzzle game in the spirit of The Incredible Machine. Each puzzle gives you a half-built Rube Goldberg machine and a bin of parts. Place the parts, press Start, and watch the physics play out. These mockups pin down the look and the core loop before we write any physics.

CONTRAPTION CONTRAPTION BUILD IT · START IT · WATCH IT GO 1★★★ 2★★★ 3★★★ 4★★★ 5★★★ 6★★★ 7NEW ▶ CONTINUE · 7 FREEFORM WORKSHOP 16 / 108 STARS 1 2
SCREEN 1

Title and puzzle select

Chunky beveled tiles and a pixel title give it the early-90s PC feel without copying any original art.

  1. 1Puzzles unlock in order. Stars reward solving with fewer parts and in less time, so there is a reason to replay.
  2. 2Freeform is an open workshop with every part and no goal. It doubles as the level editor later on.
5 CELLS ×2 ×0 ×1 ×2 ×1 ×2 ×1 ×1 ×1 ×1 10 PARTS LEFT PUZZLE 7 · SLAM DUNK GOAL: GET THE BASKETBALL THROUGH THE HOOP HINT RESET ▶ START 1 2 3 4 5
SCREEN 2

Build mode

The heart of the game. Time is frozen and nothing moves until you press Start.

  1. 1Parts with a padlock are fixed by the puzzle. Everything else on the field was placed by the player and can be moved.
  2. 2A placed ramp, bowling ball and see-saw. Every part snaps to a 20px grid so machines can be rebuilt exactly.
  3. 3Dragging a part shows a ghost with its size in grid cells. A yellow outline means it fits; it turns red when it overlaps.
  4. 4The bin holds only the parts this puzzle allows. Spent parts grey out at ×0.
  5. 5Start runs the machine. Reset puts every part back where you placed it, so you can tweak and retry.
PUZZLE SOLVED! ★★★ RUNNING TIME00:04.2 PARTS USED3 STAR GOALS ✓ SOLVE IT ✓ UNDER 6 SECONDS ✗ 2 PARTS OR FEWER ½ SPEED REPLAY NEXT PUZZLE8 · UP, UP, AWAY ✓ BASKETBALL WENT THROUGH THE HOOP ■ STOP 1 2 3 4
SCREEN 3

Run mode

The bowling ball rolls down the ramp, drops on the see-saw and flings the basketball into the hoop.

  1. 1Dotted trails show where each moving part has been. They stay on screen after Stop, which makes it easy to see why a try failed.
  2. 2The goal is checked every frame. Once it is met, the machine keeps running for a moment and then the banner appears.
  3. 3The parts bin turns into a live readout with the three star goals for this puzzle.
  4. 4The physics is deterministic, so Replay and half speed show exactly the same run every time.
FLIP BELT DEL PICK A PULLEY CONVEYOR DIRECTION→ LENGTH9 CELLS POWERMOUSE SPEED0.8 M/S Needs a belt from a powered wheel or gear to move. ◀ BACK TO PARTS FREEFORM WORKSHOP DRAG TO MOVE · R TO ROTATE · F TO FLIP ▶ START 1 2 3 4
SCREEN 4

Editing and connecting parts

The part of the original that made it feel like real engineering: belts and ropes that link parts together.

  1. 1Selecting a part opens a small toolbar above it. Belts and walls get stretch handles; ramps rotate in fixed steps.
  2. 2A belt from the mouse wheel drives the conveyor. Belts only join round things: wheels, gears and pulleys.
  3. 3Linking tools draw a rubber band from the first part and highlight every valid target until you click one.
  4. 4The bin becomes an inspector for the selected part, with a plain hint about what it needs to work.
‹ 7 · SLAM DUNK HINT GOAL: BASKETBALL THROUGH THE HOOP 100% PARTS · 10 LEFT ×2 ×1 ×2 ×1 ×2 ×1 ×1 ×1 DRAG A PART UP ONTO THE FIELD RESET ▶ START 1 2 3
SCREEN 5

Phone layout

The same puzzle, held upright. The field keeps its 4:3 shape and the bin becomes a drawer with big touch targets.

  1. 1A dragged part floats a little above your finger so you can see where it lands. A second finger rotates it.
  2. 2The drawer pulls up to show every part, or down to give the field more room.
  3. 3Pinch to zoom for fiddly placements. Grid snapping makes small parts easy to place even when zoomed out.
Parts catalogue

Starter set of 15 parts

Enough to build about 30 puzzles. Each part needs one clear behaviour that players can predict.

Bowling ballHeavy. Knocks things over and barely bounces.
BasketballLight and very bouncy.
BaseballSmall and fast. Fits through narrow gaps.
BalloonFloats up. Pops on a candle flame or scissors.
RampRotates in 15° steps. Comes in three lengths.
Brick wallStatic. Stretches in grid cells.
See-sawWeight on one end launches the other.
ConveyorMoves what sits on it, but only while powered by a belt.
Mouse wheelRuns while the mouse is awake. Powers belts.
GearMeshes with neighbouring gears and reverses direction.
TrampolineBounces anything back up higher than it fell.
BucketCatches balls. Gets heavier as it fills and pulls its rope.
CandlePops balloons and burns through rope.
ScissorsSnip shut when hit, cutting any rope across them.
FanBlows light things away. Needs power from a belt.

How it would be built

  • One index.html, no build step, like the other projects here.
  • Box2D physics through planck.js, stepped at a fixed 60 Hz so every run of a machine plays out the same.
  • Canvas rendering, with the same flat 90s art style as these mockups.
  • Puzzles stored as small JSON files: fixed parts, the bin, and a goal check.

Suggested first version

  • 8 parts: the three balls, ramp, wall, see-saw, trampoline and balloon.
  • Screens 2 and 3: build mode and run mode.
  • 10 puzzles that each teach one part.
  • Belts, ropes and powered parts come in version two.

Open questions

  • Keep a cast of characters, like a cat chasing a mouse, or stick to objects only?
  • Retro pixel art as shown here, or a cleaner modern look?
  • Should the freeform workshop let players share machines by link?