Players now
0
newvs 24h ago · updates every minute
Last 7 days
Screenshots, achievements, specs, every price change and sale we've seen on Steam, and trading cards.
Loading from Steam…
Steam prices for United States (change the country in the top bar), and Steam keys from authorized stores.
Checking other stores…
Loading from Steam…
85% positive of 56 · Very Positive · Live from Steam
Loading reviews from Steam…
Free on Steam. The demo has its own app, so its players are counted separately.
This is a puzzle game like a mathematical book, based on logic and deduction. In this game, you don't need to beat the level, but need to prove it is beatable. Your goal is not to win, but to prove you can win.
Live data from Steam, tracked by SteamPlayerBase.
What changed on Steam for this game since we started following it: prices and sales, builds, name, release date and review score.
Review score: 85% on 2026-11-01 → 85% today (56 reviews)
Games we track that share the most Steam tags with this one.
No authorized Steam key store lists this game right now.
Not tested by Valve yet. Results from Valve's own testing.
Valve hasn't published test details for this game.
Every build released on Steam for this game since we started tracking it, with the developer's patch notes. Updated within minutes of each new build.
Fix the description of prop 4.6 in English
Fix the bug: Rule 2.1 is wrongly showed in the tutorial when proving proposition 2.1.
fix some text error add macOS version (It's better to try the demo version before buying the game)
Fix some text errors and add the demo version.
Add rule5.2 assistor (similar to rule3.1)
Some code options are added in this version. Notation is supported now. (See tutorial page 3) Some text error is fixed.