Puzzles  ·  Tummelberry

A growing set of logic puzzles,
one hint engine under all of them.

Logic puzzles on square and hexagonal grids, with a new game joining the collection regularly. Most are generated by mystify, an active research project: every level it ships is proven to have exactly one solution. And every hint comes from Demystify, an open-source solver running in your browser the whole time you play — if you're stuck, it works out the next deduction on the spot and shows you why.

The mystify puzzles

11 games

Every level here was generated — and proven to have exactly one solution — by mystify, an active research project in constraint-based puzzle generation.

1 2
Mauve
Two-colour Light Up. Place red and blue bulbs so every cell is lit by both — without two same-colour bulbs in sight.
Square 2-colour
Duotone
Two-colour hex grid where no three same-colour hexes sit in a line, along any direction.
Hex 2-colour
Trichrome
Three colours on a square grid: never three the same in a row, with each colour appearing equally often in every row and column.
Square 3-colour
Oil & Water
An aquarium puzzle where connected tanks fill bottom-up with water, oil, and air.
Square Cages
Permutation
Place pieces on a hex grid — beams fire in six directions. Never let a piece cross another's colour.
Hex Drag
Gamut
Colour-mixing Light Up on a hex grid. Place R/G/B bulbs so every target is lit just right.
Hex 3-colour
4 2 2 5
Allotments
Divide the grid into numbered rectangles — each number sets its rectangle's area.
Square Regions
3 2
Sashes
Allotments on a hex grid: numbered clues anchor ribbon-shaped regions that each hold one clue.
Hex Regions
4 2 2 1 1 3 1
Patchwork
Tile the grid with coloured patches — each holds one clue, a number sets its area, and no two same-colour patches may touch.
Square Regions 4-colour
Campfire
Pitch a tent beside every tree, and warm each numbered fire with the right count of surrounding tents.
Square Counting
Rivers
Numbered heights on a hex grid, with springs, sinkholes, and rivers flowing downhill across the landscape.
Hex Counting

Earlier research

2 games

The two originals, with hand-built levels — made before mystify existed, using earlier techniques. Bloomsweeper's hints run their own solver; the rest of the collection grew out of these.

Combination
Drag attack pieces onto a grid so no piece is hit by a beam of a different colour.
Square Drag
Bloomsweeper
Deduce which herb hides in each cell from the neighbour-count clues around revealed ones.
Square Counting

Built with Demystify

The hints here aren't scripted. Demystify, an open-source solver that explains pen-and-paper puzzle deductions, is compiled to WebAssembly and runs in your browser the whole time you play. Press Where? or Why? and it solves your current board on the spot, finding the smallest set of clues that force the next step — the hint button isn't a workaround, it's the whole point. The levels themselves come from mystify, an active research project that generates each puzzle and proves it has exactly one solution before it ships. More puzzles and more types are on the way.