01
One per row, column & area
Place exactly one character in every row, every column and every bold-bordered area. Fill the board with no violations to clear the stage.
Basics
Areas are outlined with thick borders
Global Cognitive Sport
Solo
Square
One chara per row, column and area. A logic puzzle of pure elimination — no two charas may touch.
Overview
Solo Square is a logic puzzle where you place exactly one character in every row, every column and every bold-bordered area. Charas can never touch, not even diagonally. Mark impossible cells with × and deduce the single valid arrangement by elimination. Invalid placements turn red immediately and add +5 seconds to your total time. Boards are randomly generated every play with exactly one solution, growing from 4×4 to 9×9 as levels rise. Use the sample charas as clues and solve each board through deduction rather than guessing.
How to play
02
No touching
Charas can never sit next to each other — not vertically, horizontally or diagonally. Any contact within the surrounding 8 cells is a violation.
Diagonal contact is the easiest to miss
03
Sample charas
Charas marked with 🔒 are pre-placed in their correct spots as samples. They cannot be moved — use them as footholds to fill in the rest. Higher levels give fewer samples.
Hint
Look around the samples for your first move
04
Eliminate with × memos
Tapping a cell cycles × → chara → empty. Mark cells you have ruled out with × to narrow down the candidates.
Memo
× marks are just memos and never affect your score
05
Mistakes add +5s
Placing a chara on a spot that breaks a rule turns it red on the spot and adds +5s to your total time. It is not a game over, but check before you place.
+5s
Random tapping makes your time heavier
06
Stuck? Use a hint
The Hint button auto-marks every cell that definitely cannot hold a chara with × and locks it. But each use adds a big +30s penalty — a last resort when you truly cannot solve it.
+30s
The more you solve yourself, the faster your time
07
Time attack
Your elapsed time to clear is your score. Boards are randomly generated every play and always have exactly one solution.
Unique
A new board is generated every time you play
Difficulty
99 stages total. Every 11 stages, the level increases.
| Level | Stages | Grid | Charas | Deduction depth |
|---|---|---|---|---|
| 1 | 1–11 | 4×4 | 4 | Gentle |
| 2 | 12–22 | 5×5 | 5 | Gentle |
| 3 | 23–33 | 5×5 | 5 | Medium |
| 4 | 34–44 | 6×6 | 6 | Medium |
| 5 | 45–55 | 6×6 | 6 | Deep |
| 6 | 56–66 | 7×7 | 7 | Medium |
| 7 | 67–77 | 7×7 | 7 | Deep |
| 8 | 78–88 | 8×8 | 8 | Deep |
| 9 | 89–99 | 9×9 | 9 | Deep |
Abilities you'll build
Processing speed
Scanning the whole board's constraints to spot the next forced cell trains processing speed.
Working memory
You hold several row, column and area conditions in mind at once, which trains working memory.
Reasoning
Narrowing down where charas can and cannot go through step-by-step elimination trains logical reasoning.
Self-control
You must resist placing on a hunch and proceed from confirmed cells, which trains decision control.
Ability Balance
SPEED
10%MEMORY
10%LOGIC
60%CONTROL
20%Choose a Time Attack
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