Hello, I'm the solo developer behind Spectradoku, a free browser-based Sudoku variant I've been building over the past months.
I'd love to share it with you and hear what you think.
── What it is ──────────────────────────────────────────
Spectradoku is Sudoku with two layers stacked together. Every cell holds both a digit and a color, and three rules apply:
1. Digits 1–9: each row, column, and 3×3 box contains each digit exactly once. (Standard Sudoku.)
2. 9 colors: each row, column, and 3×3 box contains each color exactly once. (A second Sudoku, on the color layer.)
3. Across all 81 cells, every (digit, color) pair appears exactly once — the two layers are mathematically orthogonal.
In combinatorics this is called a Graeco-Latin square. In play, it feels like solving two interlocking Sudokus at the same time, where each layer constantly informs the other.
── What makes it different ────────────────────────────
• A genuinely new puzzle type, not a reskin. The orthogonality constraint creates deductions that don't exist in standard Sudoku.
• Pure logic, no guessing. Every puzzle is verified solvable by human techniques alone — no bifurcation or trial-and-error needed.
• Five difficulty tiers, from a gentle Intro that teaches the two-layer notation, up to Expert puzzles that take 30+ minutes even for experienced solvers.
• Built for everyone. Works on phone, tablet, and desktop. Notes mode, eraser, hints, undo, and per-puzzle auto-save are all in.
• Completely free. No signup, no paywalls. Plays instantly in any modern browser.
── Try it ──────────────────────────────────────────────
https://spectradoku.com
If the Intro tier feels too easy after a puzzle or two, jump straight to Expert — that's where the variant really opens up.
── If you'd like to cover it ──────────────────────────
I'd be delighted to support coverage in any form: a written review, a video walkthrough, a social post, or a community feature. I can also create custom puzzles tuned to a specific theme, difficulty, or solving technique if that would help your content. No expectation either way — even just trying a puzzle and sending back a one-line reaction would mean a lot.
Thanks for taking a look.
I'd love to share it with you and hear what you think.
── What it is ──────────────────────────────────────────
Spectradoku is Sudoku with two layers stacked together. Every cell holds both a digit and a color, and three rules apply:
1. Digits 1–9: each row, column, and 3×3 box contains each digit exactly once. (Standard Sudoku.)
2. 9 colors: each row, column, and 3×3 box contains each color exactly once. (A second Sudoku, on the color layer.)
3. Across all 81 cells, every (digit, color) pair appears exactly once — the two layers are mathematically orthogonal.
In combinatorics this is called a Graeco-Latin square. In play, it feels like solving two interlocking Sudokus at the same time, where each layer constantly informs the other.
── What makes it different ────────────────────────────
• A genuinely new puzzle type, not a reskin. The orthogonality constraint creates deductions that don't exist in standard Sudoku.
• Pure logic, no guessing. Every puzzle is verified solvable by human techniques alone — no bifurcation or trial-and-error needed.
• Five difficulty tiers, from a gentle Intro that teaches the two-layer notation, up to Expert puzzles that take 30+ minutes even for experienced solvers.
• Built for everyone. Works on phone, tablet, and desktop. Notes mode, eraser, hints, undo, and per-puzzle auto-save are all in.
• Completely free. No signup, no paywalls. Plays instantly in any modern browser.
── Try it ──────────────────────────────────────────────
https://spectradoku.com
If the Intro tier feels too easy after a puzzle or two, jump straight to Expert — that's where the variant really opens up.
── If you'd like to cover it ──────────────────────────
I'd be delighted to support coverage in any form: a written review, a video walkthrough, a social post, or a community feature. I can also create custom puzzles tuned to a specific theme, difficulty, or solving technique if that would help your content. No expectation either way — even just trying a puzzle and sending back a one-line reaction would mean a lot.
Thanks for taking a look.
