Academics
Proof Sweeper
Minesweeper where nothing opens until you prove it: pick a square, claim safe or mine, name the rule (done / full / subset) and tap the numbers that force it. A checker accepts only steps that really follow from what is open plus the mines you have already proven, and each accepted step becomes a numbered line of your written proof. Harder levels require the subset rule. You cannot lose, only prove. On-device. Ages 15-18.
▶ Play it nowBuilt for sittings of about 25 minutes on the screen. That is our design budget, not a measurement.
#4A3F8C Characters who teach
Meet the cast
Proof Sweeper is for ages 15-18: the three RULES OF INFERENCE are the cast — done, full and subset — and ten case personas (see Proof cases). Lucia, a quick player whose teacher keeps writing 'why?', learns that a claim is only proven when she can name the rule and the facts that force it.
Lucia
(Case persona, 17) - learns a claim is proven only when she can name the rule and the premises that force it
Theo
(Case persona, 16) - learns every proof starts from a given — here, the safe opening
Amara
(Case persona, 15) - writes her first line: a claim, a rule, and the premise number
Felix
(Case persona, 17) - learns a premise only proves things about its own neighbours
Yuki
(Case persona, 16) - writes the subset rule smaller set first — order is part of the meaning
Omar
(Case persona, 17) - proves a mine before using it — a hunch cannot be a premise
Beatriz
(Case persona, 15) - reads a rejected step as a to-do, not a verdict
Sven
(Case persona, 16) - finds a sound checker can never be tricked into a false step
Zara
(Case persona, 17) - measures that a puzzle needs the rule it claims to teach
Nikhil
(Case persona, 16) - sees a proof as a chain each line of which can be checked from the lines above
What's inside
Learning goal
Minesweeper where nothing opens until you prove it: pick a square, claim safe or mine, name the rule (done / full / subset) and tap the numbers that force it. A checker accepts only steps that really follow from what is open plus the mines you have already proven, and each accepted step becomes a numbered line of your written proof. Harder levels require the subset rule. You cannot lose, only prove. On-device. Ages 15-18.
Mentored by Lucia — no data leaves the device.
How Proof Sweeper handles your kid's data
- ✅ All progress, settings, and AI-generated content stays on the device
- ✅ No analytics, no tracking, no third-party SDKs
- ✅ Free — no ads, no in-app purchases
- ✅ No personal information collected from children — in line with COPPA (updated by the 2026 FTC amendments)
- ✅ No chat with strangers — play-together rooms use a short code and preset emotes, never typed messages
