01
Sparks grow you
Orange diamond · +1 length · +1 heat · lands in the largest empty area
Eat a Spark and the coil grows by one cell. Each Spark adds one heat. At heat 3 the corner brackets light.
On Google Play
filament
Fill every cell.
A coil of light glides across a 9 × 16 board. Sparks grow it. Stamps shrink it and leave Embers behind. Coil and Embers both count.
Get it on Google Play9 × 16 board · 285 ms a step · edges wrap · hit yourself and the run ends · no ads
Heat
Swipe to start
The coil
It glides.
Head and tail move every frame, so the coil never jumps a cell. When the speed changes it eases in over about 300 ms. At an edge it slides out of one side and back in at the other.
- Round corners on every turn
- The tail tapers and its glow narrows with it
- The eye on the head leads the way it moves
How a run works
02
Stamps shrink you
Ring beside your tail · last 2 tail cells become Embers · heat back to 0
Stamps drop next to your tail, so you loop back for them. The head steps on, the last two cells of the tail stay behind as Embers, and the coil comes out one cell shorter. Embers count as filled, and you can cross them.
03
Run hot, then brake
Heat 3 runs 22% faster, heat 4 38% · Sparks clear at 4 · hold = half speed · 0.8 s hold = −1 heat
Heat speeds the coil up. At 4 the Sparks clear until you cool down. Hold anywhere to brake: the board dims and the coil runs at half speed. Hold for 0.8 seconds and heat drops by one. Cooling off 4 brings a Spark back.
04
Fill every cell
Coil + Embers = 144 of 144 · relights in fill order · next cycle 6% faster
The fuller the board, the faster the coil. Cover all 144 cells with coil and Embers and the board relights in the order you filled it. Your Glyph is saved, and Play again starts the next cycle 6% faster: 285 ms a step becomes 267.
First run
A first run that teaches.
New players start on a 5 × 7 board they cannot lose. Four steps, and each one needs a real move: Swipe, Stamp, Heat, Fill. A ghost finger shows the move until you make it. Run into your own coil and it only stops.
Swipe to turn.
Turn toward the Spark. Sparks make you longer.
Daily and challenges
A Daily, and nine challenges.
The Daily Glyph is the same board for everyone that day. Challenges give a run one goal. Fill more boards and keep your Daily streak to open the rest.
Daily Glyph
Same board for everyone today
- Daily GlyphToday’s board, same for everyoneOpen
- ≤12 StampsFill with ≤12 StampsOpen
- Wrap RunnerWrap an edge 8+ times, then fill2 more fills
- Never Heat 4Fill without reaching heat 43 more fills
- Single StampFill with at most 1 Stamp4 more fills
- Heat RaceReach heat 4, then fill5 more fills
- Speedrun 90sFill in 90 seconds3 more days
- Stamp Cool OnlyFill, cooling only with Stamps5 more days
- No BrakeFill without braking7 more days
As a new player sees them. Pro adds looks and modes; it does not skip this ladder.
Fill every cell.
Get it on Google PlayOn Google Play
Terms
The short version. The full terms decide.
- Your licence. Unit Labs gives you a personal, non-transferable licence to play filament on devices you own or control. The game, its code, art and name stay ours.
- Free, with an optional Pro. The game is free on Google Play. Filament Pro is a one-time purchase that Google Play bills: more themes, coils and modes, and Share Glyph. It does not skip the challenge ladder.
- Refunds. All sales are final, except where the Refunds policy, Google Play's own policy or the law says otherwise. If Google Play refunds Pro, Pro is removed. Restore purchases brings it back on a new install.
- Your data stays on your phone. Progress, settings and Glyphs live on the phone, and there is no Filament server. Uninstalling or clearing storage deletes them. Play Games sign-in is optional. Pro is checked with Google Play and keeps working offline for 7 days after the last check.
- Fair play. Do not cheat the Play Games leaderboards or achievements, or tamper with the game. Scores gained by cheating can be removed.
- No warranty. Filament comes as it is offered on Google Play. Liability is capped at what you paid for Pro in the 12 months before a claim. The laws of India apply.