Weekly challenge
From 9 November 2026 there's a 9×9 Sudoku for everyone every week – with a special rule that changes weekly. It's a puzzle of its own, unrelated to daily puzzles and duels; solving the weekly challenge earns you 150 XP once per week. The order: Fog, Mirror, Three lives, No notes – then it starts over.
🌫️ Fog
You only see the row, column and box of the selected cell (plus the cells right next to it) – move through the fog to read the board.
🪞 Mirror
The solution is mirrored through the centre: opposite each digit sits its partner to 10 (3 ↔ 7, the centre is 5). Every correct digit fills its mirror cell for you.
❤️ Three lives
You have three lives. The third mistake ends the challenge – but you can start again.
🧠 No notes
The pencil stays in the drawer this week: everything happens in your head.
Advent calendar
From 1 to 24 December a door opens every day, with a special puzzle behind it – different puzzle types mix in, the first week to warm up, the last one to puzzle over. A door opens on its calendar day in your local time, like a real Advent calendar. There are XP and two trophies to earn.
Your progress belongs to your account – every device shows the same calendar. A tile on the start screen shows which door is today's.
Solve together
Up to four people solve the same Sudoku at once. Every correct digit appears on everyone's board immediately – and everyone has their own colour so you can see who placed what. Mistakes cost all of you time – so coordinate.
- One person creates a room via Solve together and gets a code plus a link.
- The others join with Join – enter the code or tap the link.
- You gather in the waiting room. As soon as someone joins, the board is revealed and the clock starts – so you all begin together. You can also start alone for now.
- The penalty time is shared: if someone makes a mistake, the seconds go to the whole team. At the end you see the shared time including mistakes.