Sphere your way to genius.
Fit coloured segments into a perfect pyramid of balls. Open science, free puzzles, a real aha in your hands.
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The maths is the toy.
Spheromino is built on the way spheres actually stack. Every rule you feel in your hands is a real result from geometry and combinatorics.
Twelve neighbours, not six. In close packing each ball touches twelve others — two balls kiss exactly when the quadratic form Q(Δ)=1.
Triangular & tetrahedral. Layers grow 1·3·6·10·15 and sum to 35 — the 5th tetrahedral number. Segments of 1–5 balls fit an edge of exactly 5.
Rare by design. Of ~32,164 possible segment sets, at least 435 truly tile the tetrahedron — and the solver keeps finding more.
Twelve orientations. The tetrahedron's rotation group turns one solution into a whole family of puzzles.
Read five layers. Return the hidden pieces.
Coloured balls are placed for you; white holes are the segments you must find. Here's one to try — then browse the whole free library.
Colours are placed for you; the white holes are the pieces to return.
Not stuck — just one aha away. Toggle the solution when you want to check yourself.
Prints the puzzle to solve on paper. Reveal the solution first to print the coloured answer.
Four ways to hold one.
The puzzle is open. Buy one, print one, or build it from things you already have.
Existing puzzles
Compatible sphere puzzles you can pick up today.
3D print · STL
Free models on Printables — print the segments and go.
Beads
Glue craft beads into segments for a few coins.
Floorball balls
Wiffle-style balls make a big, huggable set.
The Genius Brochure
A curated PDF of the hardest, most elegant tasks — the ones that never touch the free library. Print, solve, frame the good ones.
- 50 hand-picked puzzles — 25 Genius + 25 Advanced
- Verified-unique, print-ready, colourblind-safe
- Pay once, download forever — no account
Built between a toy and a theorem.
Spheromino started as a spreadsheet full of stacked spheres. Now it's an open puzzle anyone can try, print, and share. Follow along as new tasks unlock.
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