How to play

Game basics

polyomino.io is a free real-time multiplayer game played in your browser. You start as a single coloured square — a mino — drifting through a shared arena alongside other players, bots, and edible food tiles scattered across the floor. As you collect food of your colour, your mino grows into a polyomino: a 2-cell domino, a 4-cell tetromino, or a 5-cell pentomino, depending on which mode you chose. Once your figure is complete you can dock it onto the playfield to score, and the cycle starts over with a new single mino in a fresh colour.

Every mode shares the same core verbs — collect, dock, score — but each one wraps them in a different objective: FFA is a territory land grab, Pentomino a cooperative picture puzzle, Domino a bridge-building race, and Triomino a collect-and-deliver run. You can switch between them at the start screen by tapping the Mode card.

Choosing a colour and food

Every player and every food tile has a colour. Your starting colour is assigned on spawn, and in most modes you can only eat food that matches your colour — eating a mismatched tile costs you a mino (or your life, if you only had one). Domino mode is the exception: any colour docks, so you eat freely.

Bumping into other players

When two players collide cell-to-cell, what happens depends on their colours. Same colour: you both bounce off and keep going. Different colour: both players lose the touching mino (or die if it was their last). This rule is the reason a complete figure surrounded by enemies is dangerous — every contact costs a piece.

Controls

Desktop (mouse)

• Move: Your figure follows the mouse. The further the cursor is from the centre of the screen, the faster you go — pull the cursor in close to glide, push it to the edge to sprint. There is no "stop": you always drift in the last chosen direction.
• Shoot / Drop: Left click. In FFA, this fires a recoil shot — your rear-most mino flies off as a projectile, and your figure shrinks by one; the shot knocks a mino off a rival, or a tile off a rival's block. In Pentomino, this triggers your figure-drop onto the picture (only fires once you have all 5 minos). In Domino there is no shooting.
• Rotate: Right click. Rotates your figure 90° clockwise. Useful in FFA for shaping your block, and in Pentomino for aligning your 5-mino shape with the next missing slot.

Mobile / touch

• Move: Touch anywhere on the playfield to summon a virtual joystick at your fingertip, then drag to steer. Lift your finger and your figure keeps gliding at the last direction and speed.
• Shoot / Drop: The round button in the bottom-right corner.
• Rotate: The curved-arrow button next to the fire button.

Audio & theme

In the upper-right corner you can toggle the ♪ background soundtrack and fx sound effects independently. The ☀ button at the very top switches between the light and dark themes; your choice is remembered between sessions.

FFA mode

FFA is the headline free-for-all — a real-time land grab on a shared square arena. The moment you take the field you are handed a small solid block of tiles in your colour: your territory, and the only stones you are allowed to dock onto. Your single live mino starts just above it. Collect food of your colour to build a four-cell tetromino, exactly like the classic pieces, then bring it home to grow your block.

Growing your territory

Once your figure is a complete tetromino, fly it into your own block and it docks there, extending your territory. You can only dock onto tiles you already own, so you are always growing outward from your starting block. The dock lands against any of the four faces, and a short lock-delay lets you settle the piece before it commits. Crucially, only the tiles you dock through play count toward your share of the arena — the free starting block banks no progress on its own.

Recoil shot & breaching blocks

Left click (or the fire button) fires a recoil shot: your rear-most cell detaches and flies off as a projectile, and your figure shrinks by one, so you need at least two cells to fire. A shot that hits another player costs them a mino, or kills them if it was their last cell. A shot that hits a rival's block vaporizes a single tile of it — one shot, one mino — letting you breach an enemy's wall and shave their coverage a tile at a time. Your own tiles are immune, and the projectile slows over time and dies after ~1.8 s.

Ramming and eliminating

Fly a completed figure into a rival's territory instead of your own and it is destroyed on impact — vaporized for a bonus, but no tile is docked for you. The headline kill is the connect: dock a figure so its new tiles land right next to a rival's block, and you have fenced them in. That rival loses every heart, dies on the spot, and their whole block bursts off the board, freeing the ground for you to claim.

Lives

You have three lives, shown as ♥ ♥ ♥ in the top-left HUD. Losing your last cell burns a heart and respawns you — your territory survives a heart loss. Run out of hearts and you are out, and every tile you owned vanishes with you.

The win: cover the arena

Blanket a quarter of the arena with your own docked tiles and you win the round: you score the win bonus, the board wipes, and everyone reseeds with a fresh block for the next round. Growing outward, breaching rivals, and connecting to wipe them all free up the space you need to get there first.

Surprise stones

Up in the top section of the well you'll spot glowing white stones — one appears for every four players in the room (bots included). Touch one and you grab a random super-power for the life of your current figure. There are three:

• 🌈 Rainbow — eat stones of any colour for points without losing a mino; only your own colour still docks.
• 🧩 Full figure — instantly completes your tetromino, but only if you were carrying fewer than four minos when you hit the stone.
• ⚡ Speed boost — move 50% faster.

The power lasts only until you dock and respawn (or die) — then it's gone, and you'll need a fresh stone to get another. An active rainbow or speed power shows as a glowing badge under your score.

Pentomino mode

Pentomino is the picture-filling mode. Each room is built around a single picture — a heart, a star, a car logo, and so on — laid out in the centre of the world as a faint outline. The full picture is made of dozens of coloured cells in several different colours, and the players' shared job is to fill it in.

The figure

Your figure in Pentomino is a 5-cell pentomino: the same kind of shape that gives the game its name. You grow from one mino to five by eating food of your colour, picking up any free pentomino arrangement along the way (it depends on which cells happen to be available when you eat). Rotation works exactly the same as in Tetromino — right click or the rotate button spins the whole figure 90°.

Dropping onto the picture

Once you're a full pentomino, fly into the picture outline in the middle of the world and trigger your drop. Every one of your five cells is checked against the picture: if the cell sits on top of an unfilled picture cell of your colour, that cell locks in and earns you 10 points. Cells that miss — empty space or a wrong colour — are lost and fade out at the spot they landed. As long as at least one cell matched, the drop succeeds and you respawn with a fresh single mino after a short cinematic.

Drop with zero matching cells and you die. The penalty for sloppy alignment is steep, so it's worth taking a beat to rotate into the cleanest fit before committing.

Completing the picture

When the last unfilled cell locks in, the picture is complete. The player who placed the final piece earns a 100-point completion bonus, the picture is wiped, and a fresh round of the same picture begins.

Colour rerolling

The picture only uses a handful of colours, so after enough cells have been filled, some colours run out before others. Once a colour has no unfilled cells left, every alive player who was that colour is automatically rerolled to a colour the picture still needs — without it, those players would be unable to score on their next drop.

Domino mode

Domino is a quick, tactical bridge-building race. The world is a 100×100-cell square. The top and bottom walls are plain grey and do nothing; the cyan left wall and orange right wall are dockable, each in their own colour.

The figure

Domino figures are tiny: just two cells. You spawn as a single coloured mino, eat any food at all to grow into a domino, and you're ready to dock. Unlike the other modes, Domino food docks regardless of colour — your domino can end up two-toned, and that's fine.

Docking

A domino docks only when one of its cells touches a wall or another docked stone of the same colour. That's the whole rule. Drift up to the cyan wall with a cyan cell and you'll dock to it; an orange cell touches nothing. Once docked, your stones snap to the grid and the colour of each cell is preserved on the board.

The win: bridge wall to wall

The round ends when the docked stones form an unbroken 4-connected chain that touches both the cyan and the orange wall — any path, any colours, just connectivity matters. The player who placed the final connecting stone earns a 100-point pattern bonus, the board wipes, and a fresh round begins. Domino rounds are short, and a single well-placed stone can finish a chain that took several players to set up — endgame is where it counts.

Arena (private match)

Arena is a private room. Pick a pin code at the start screen and your friends can join the same room by entering the same code. Arena rooms have no bots — only the players who joined — and the first player in the room is the admin: they pick the game, the rules, and start the round.

• Respawn: Standard rules. Players who die respawn after the usual countdown. Good for casual free-for-all between friends.
• Hardcore: One life. When you die you become a spectator for the rest of the round and can pan the camera around the world to watch the survivors. The last player standing wins, and the admin starts the next round when everyone's ready.

If the admin leaves mid-round, the round auto-ends shortly afterwards so the remaining players aren't stuck in limbo.

Scoring at a glance

• Dock a complete figure (FFA / Domino): +25 points.
• Lock a pentomino cell into a picture: +10 per matching cell.
• Complete a picture, bridge, or cover the arena: +100 bonus.
• Ram a figure into a rival's territory (FFA): +15 to the pilot.
• Eat food while already at max figure size: +3 per tile (FFA / Pentomino).
• Hit another player with a projectile: +5 if they lose a mino, +10 if it was their last.
• Chip a tile off a rival's block with a shot (FFA): +5.

The current leaderboard for your room is shown in the top-right HUD during play.

Tips

FFA

• Grow toward your rivals, not away from them. Every dock you land next to an enemy block risks connecting to it — and connecting fences them in and wipes them off the board.
• Use shots to breach, not just to kill. Chipping a hole in a rival's wall opens the ground behind it for you to flood with your own tiles.
• Only docked tiles count toward the win, so keep building — a fat starting block is worth nothing on its own. Cover the most ground and the round is yours.

Pentomino

• Rotate before you commit. A drop with one matched cell is barely worth it; a drop with all five is worth 50 points plus a shot at the 100-point completion bonus.
• Watch the leaderboard for who's close. If someone else is one drop away from completing the picture, race them — completion bonuses are where the big scores come from.
• If your colour stops appearing in the picture, you'll be auto-rerolled. Don't waste a perfect-looking drop on the wrong colour just before that happens.

Domino

• Don't always build toward the centre. Sometimes the fastest path to a win is to attach a single stone to an opponent's half-finished chain rather than starting your own.
• Mismatched stones still block movement. A row of "useless" colours can be used to wall off opponents from a promising line.
• The win bonus goes to whoever places the last stone, not whoever built most of the chain. Save your move for the close-out.