Sudoku has nothing to do with arithmetic. You never add the numbers, never compare them, never put them in order. They are just nine symbols that have to appear once in each row, column and box, and any nine symbols would do the same job. So this game lets you swap them out for pictures.
Pick sprouts and toadstools, pancakes and coffee, moons and comets, or keep the numerals if that is what you grew up with. The puzzle underneath is identical and so is every technique for solving it.
Who this actually helps
Taking the digits out is not decoration. It changes who can play.
- Children who can do the logic before they are fluent with numbers. Matching and elimination come early. Reading a grid of digits at speed comes later. A picture board lets the first happen without waiting for the second.
- People with dyscalculia. A page of numerals can be genuinely tiring to parse even when the reasoning is easy. Shapes and colours cost much less to tell apart.
- Anyone who wants a quieter board. Some people simply find a grid of flowers a nicer thing to look at for twenty minutes than a grid of digits.
Why every set shares nine colours
Each set uses the same nine colours in the same nine positions. The first value is always the same warm red whether it is a sprout, a macaron or a snowflake. That is deliberate: it means switching sets costs you nothing you have already learned. The board changes mood without changing the thing your eye has been trained to look for, and you can swap mid-puzzle.
It also means colour is never the only signal. Every glyph in a set has its own distinct silhouette, so the board still reads if you cannot separate two of the hues.
The twelve sets
Getting started with a child
Start on Cozy, which never needs anything harder than spotting the last empty square in a row or box, and pick a set they like the look of. The first thing to teach is not a technique, it is the rule: nine of each, one per row, one per column, one per box. Most children find the last free square by themselves within a few minutes of understanding that.
Turn on Highlight in settings so the row, column and box of the square they are on light up. It makes the rule visible instead of something they have to hold in their head, and it is the single most useful setting for a beginner of any age.