For grown-ups
Bug Hunt is a logic puzzle. Sleeping bugs hide under some of the leaves, and each number says how many bugs touch that square. Your child uses the numbers to open every safe leaf.
Every garden can be solved by thinking, without guessing. A computer checks each garden before it is shown. When your child is stuck, the Why-Coach usually points to the one number that settles a square and says why; when no single number does, it suggests looking at two numbers together. Your child still makes the move.
The bugs are friendly and asleep, and nothing explodes. Opening a leaf with a bug under it wakes the bug and ends that garden, and your child can start again.
There is no score, no streak and no timer, just a count of gardens cleared, kept on this device. Nothing about your child leaves the device.
What it never does
- No accounts, no ads, no tracking: anything kept stays on this device.
- No streaks, timers to beat, points to chase or leaderboards.
- No chat, and nothing anyone types is sent anywhere.
We describe what Bug Hunt is designed to practise. We do not claim it raises test scores.
The grown-up side of the same idea, on Spark & Whetstone, our free site for grown-ups: The Daily Table. The same no-guess Minesweeper, made for grown-ups — then play Flags together.
📜 Where this game comes from
Mine-clearing number puzzles
Grid games where numbers tell you how many hidden mines are next door appeared on home computers in the early 1980s. The best-known version was made by Curt Johnson, and ported to Windows by Robert Donner; it came out in a Microsoft Entertainment Pack in 1990 and then with Windows 3.1 in 1992. In that classic game some boards force a guess, often a coin toss between two squares.
One thing to hold: Each number is a promise about the eight squares around it, and nothing else.
Why it matters: In 2000 the mathematician Richard Kaye proved that deciding whether a board’s numbers can all be true is among the hardest problems in a famous class called NP (it is “NP-complete”). A quick way to check any board would answer one of the biggest open questions in mathematics.
What we don’t know: Who wrote the very first one is still argued about; several early games had the same idea.
Dates:
- 1990 Curt Johnson and Robert Donner’s game ships in a Microsoft Entertainment Pack.
- 1992 It comes with Windows 3.1.
- 2000 Richard Kaye proves the board-checking problem is NP-complete.
Sources: Richard Kaye, “Minesweeper is NP-complete”, The Mathematical Intelligencer 22 (2000) · Microsoft Windows 3.1 (1992) · Wikipedia, “Microsoft Minesweeper” (read 2026-10-20)