What is it?
A 3D science puzzle lab. Place mirrors, wires, ramps and pipes to solve 50 experiments in light, electricity, motion, chemistry and nature, or race up to eight players online to solve them first. Touch and gamepad supported.
EUREKA LAB is a science puzzle game built with three.js. Each of its 50 experiments is a small board on a lab bench. Some parts are fixed in place, such as lasers, batteries, reagent bottles or balls, and a tray holds the parts you are allowed to add. You place mirrors, wires, ramps, pipes or filters on the free tiles, press Run, and the experiment plays out. If every goal is met, a Eureka card explains the principle the board just showed.
The experiments come in five chapters of ten. Light covers reflection, colour filters, prisms and additive colour. Electricity covers closed circuits, series and parallel bulbs, diodes, short circuits and switch logic. Motion is a side-view wall board where balls trade height for speed. Chemistry uses pipes, real reaction equations, ratios and pH. Nature links the other four, for example a solar cell that powers the electrolysis of water.
Stars depend only on how many parts you use: three stars at or under the stage's target count, two stars for up to two parts more, and one star otherwise.
Gameplay video and screens
How to play
- Pick a part from the tray (1–9, Q/E) and click an empty tile to place it.
- Click a placed part again or press R to rotate it; right-click or Delete removes it.
- Press Enter (or ▶ Run) to run the experiment. If it fails you'll see why — fix it and try again!
- Fewer parts means more stars (★★★). Stuck? 💡 Hint shows one tile.
- In a race everyone gets the same experiment at once; the server reruns each solution and scores the order of correct answers. Bots can fill empty seats.
Modes
- Solo Lab
- Fifty experiments in five chapters. The first experiment of every chapter is open from the start, and solving a stage with at least one star opens the next one in that chapter.
- Race Friends
- Create a room and share the invite link; up to eight players. Everyone gets the same stage at the same moment, and finishing places earn 10, 7, 5, 4 and 3 points, plus 2 for a three-star solution. The host picks one, three or five rounds, 90, 150 or 240 seconds per round, and one chapter or all of them.
- Bots
- Empty race seats can be filled with bots at Easy, Normal or Hard. A bot submits the stage's reference solution after a delay based on the stage's difficulty, its part count and the bot's skill, so Easy bots sometimes run out of time on harder stages.
Controls
| Action | Mouse & keyboard | Touch | Gamepad |
|---|---|---|---|
| Choose a part | Keys 1–9, Q / E, or click the tray | Tap a part in the tray | LB / RB |
| Place or rotate | Click a tile (click a placed part to rotate it), or Space at the cursor | Tap a tile, tap a placed part to rotate it, or drag a part from the tray | A |
| Rotate | R or the mouse wheel | ↻ button | X |
| Remove | Right-click, Delete or X | Press and hold, or the ✕ button | B |
| Move the cursor | Arrow keys or WASD | Tap the tile directly | D-pad or left stick |
| Run or stop | Enter | ▶ Run button | Y |
| Undo / hint | Z / H | ↶ and 💡 buttons | LT / RT |
| Pause menu | Esc | ☰ at the top left | Start |
Good to know
- The first experiment of every chapter is open from the start — begin with the science you're curious about.
- Race friends: everyone solves the same experiment; solve first for more points (up to 8, bots too).
Strategy tips
Read the failure line
When a run fails, the line above the tray names the first problem: which colour reached a sensor, a short circuit, a spill, how far a balloon or flask is from its goal, or a bulb's state under a particular switch combination. The failed goal is also ringed in red on the board.
Colours add up
A sensor needs exactly its ring colour. Red, green and blue beams add together, so two beams arriving from different directions mix just as a combined beam would. A filter keeps only the colours it is made of, and a prism always sends red to one side, green straight on and blue to the other side.
Series dims, parallel stays bright
One 1 V cell and one bulb make a bright bulb. Two bulbs in series share the voltage and both glow dim, while bulbs on separate branches both stay bright. Two cells on a single bulb burn it out, and adding the 2 Ω resistor in series brings it back to a dim glow.
Height is stored speed
On the wall board every row a ball falls adds one unit of speed and every row it climbs costs one, so a ball cannot end up higher than it started unless a conveyor adds energy. Mats take one unit per tile, springs bounce a ball back with the speed it arrived with, and there is no friction in the air.
Match the coefficients
Reactions follow balanced equations, so 4 H₂ need exactly 2 O₂, and an acid flask turns neutral only when the same number of base units arrives. A bottle opens only when a pipe faces it, so leaving the wrong bottle unconnected is often the answer. An open pipe end spills and fails the run.
Junctions split and merge
A junction where one line comes in sends units alternately down each branch, which divides a flow evenly between two flasks. Where two lines come in it merges them toward the flask, never back up the other line.
No hints in races
The hint button is disabled in races. Your board is still run on your own device first and only a working solution is sent; if the server disagrees you can send again after 1.5 seconds.
At a glance
- Genre
- Puzzles & cards
- Players
- 1–8
- Price
- Free
- Available languages
- Korean · English · Japanese · Chinese · Spanish
- Platform
- Web browser (no install)
- Mobile
- Works in portrait or landscape. You can also drag parts from the tray.
Developer notes
Placements, not scores
The browser never reports stars. It sends the list of placed parts, and the server runs the same experiment code to decide whether the stage is solved. A guest's best solutions are kept on the device and rechecked by the server when the player signs in. The engine uses only whole numbers and basic arithmetic, so the browser and the server always reach the same result.
A circuit solver on a grid
Every tile edge is a node, and even wire pieces are tiny resistors, so the animation knows the current in each piece of wire. Cells are 1 V sources with a small internal resistance, bulbs are 1 Ω, and diodes are solved by switching them on or off until the result is consistent. Stages with lettered switches are solved once for every switch combination, which is how the AND, OR and NOT stages are checked.
Checking all 50 stages
Every stage ships with a reference solution, and automated tests run all 50 and confirm that an empty board fails. I also searched every placement using fewer parts than the reference, up to about four million combinations for the hardest stages. That search found shorter solutions for three stages, and those became the references.
Update history
- First release: 50 experiments in five chapters, online races for up to eight players with bots, touch and gamepad controls, and five languages.
Questions and answers
Do I need an account?
No. Every experiment and race works as a guest, and your progress stays on that device. If you sign in with GameNow later, the server reruns your saved solutions and moves the cleared stages to your account. Rankings and race points need an account.
Do hints cost stars?
No. Stars depend only on how many parts the working solution uses. The result card shows how many hints you used.
Can I play on a phone?
Yes, in portrait or landscape. Tap a tile to place, tap a placed part to rotate it, press and hold to remove it, or drag parts from the tray.
Does it support gamepads?
Yes. A standard gamepad covers the board, the menus and races, and Select opens the GameNow menu.
How realistic is the science?
The boards simplify things: light travels in four directions on a grid, a ball's speed is a whole number, and chemicals move as single units. The rules underneath follow real principles such as the law of reflection, Ohm's law, conservation of energy and balanced reaction equations, and each Eureka card states the real principle.
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