Mirror Sudoku

Classic sudoku, and one more rule.

Every square has a partner directly opposite it, across the centre of the board. The two always add up to ten. Fill one and the other follows. The middle square is always five.

That single rule changes how a grid is read. Half the board is a consequence of the other half, and the deductions run through the centre as well as along rows, columns and boxes.

WHAT IS IN IT

• 200 levels across five worlds, each world with its own palette, getting harder inside a world and across them
• A daily challenge, the same puzzle for everyone, with a streak to keep
• Quick play at five difficulties, from Easy to Master
• Every puzzle has exactly one solution and can be solved by logic alone, no guessing, at every difficulty
• Hints that explain the reasoning instead of filling the square for you
• Wrong digits stay marked in red with the reason they cannot be right, so you always know where you stand
• Notes that update on both sides of the mirror at once
• Undo, a saved board you can return to, and a green line that shows the mirror pair you are working on
• Stats, technique badges and 26 achievements

MADE TO BE LOOKED AT

• Two typefaces, five world palettes, light and dark themes and an AMOLED black
• Every animation has a reason to exist. Nothing bounces
• Portrait and landscape, phone and tablet

PLAYS THE WAY YOU DO

• A left-handed pad layout
• Colour-blind marks wherever colour carries meaning
• System text sizing, with every screen laid out to fit
• Haptics and music you can turn off
• A relaxed mode with no mistake limit
• Screen-reader support throughout, including the mirror placements

QUIET BY DEFAULT

• No lives to wait for, no energy meter, no interruption in the middle of a puzzle
• No banner ads on the board, ever
• Rewarded ads only when you ask for one
• One optional purchase removes the ads between levels and adds two themes, unlimited undo and relaxed mode; every puzzle is free to play without it
• Eleven languages
• No account, no sign-in; your progress stays on your device

Opposite squares add to ten. Everything else follows from that.