MobiusSweeper — Especialista

What is MobiusSweeper?

MobiusSweeper is Minesweeper played on a rotating 3D Möbius strip. The strip is a single-sided surface with one edge — if you trace a path along the full length of the strip, you return to your starting point with your orientation flipped. This topological twist affects the game: cells at the seam (the join point of the strip) are adjacent to cells on the opposite row of the other side, which is the defining challenge of the variant.

The board is laid out as a grid of W rows × L columns, where columns run around the loop and rows run across the strip width. Interior cells have 8 neighbours; row-edge cells have 5 (the strip edges are real boundaries); seam cells have 8 neighbours but 3 of them come from the twisted other side.

How to Play

• Drag the strip to rotate it in any direction.
• Left-click a cell to reveal it. Empty cells (0) auto-expand through connected empty neighbours, including across the Möbius seam.
• Right-click a cell to place a flag (🚩). Right-click again for a question mark (?), and once more to clear it.
• The Flag button puts you in flag mode — left-clicks place/cycle flags instead of revealing cells.
• The ↺ button resets to a fresh board. Your timer starts on the first click.
• Win by revealing every non-mine cell.

Board Sizes

• Beginner — 4 wide × 40 long, 160 total cells, 16 mines (10%). No-Guess mode available.
• Intermediate — 8 wide × 80 long, 640 total cells, 64 mines (10%). No-Guess mode available.
• Expert — 16 wide × 160 long, 2560 total cells, 256 mines (10%). A long strip designed for extended play.

The Möbius Twist

At column 0 and column L-1 (the seam where the strip joins), adjacency crosses to the opposite side with the row index flipped. If you are in row r at the seam, your neighbours across the seam are in row (W-1-r) — the mirror row. This means a cell in row 0 is adjacent to a cell in row W-1 across the seam, and a cell in the middle rows is adjacent to a cell equally distant from the opposite edge.

Strategically, this creates unexpected connections. A chain of empty cells can flood-fill across the seam and reappear on the other side of the strip in mirrored rows. High-numbered cells near the seam are constrained by neighbours on both sides of the twist — rotate the strip to see both contributions before flagging.

No-Guess Mode

When No-Guess is enabled (Beginner and Intermediate only), the board is guaranteed to be solvable using logic alone — no guessing required. The generator uses constraint propagation and retries up to 200 times to find a valid layout. If no solvable board is found, it falls back to a random board.