QUANTMATRIX GAMES / DAILY PUZZLES
MIND LOCK
One secret code. Eight chances.
Crack a four-digit code using exact and misplaced clues. Play a free daily deduction puzzle or unlimited practice in English and Portuguese.
How to play
Choose four different digits from 1 to 6. A green marker means one digit is correct and in position. Yellow means a correct digit in another position. Markers do not identify which digit they describe. You have eight guesses.
A useful first strategy
Start with four different digits. Compare how the count of exact and misplaced markers changes between guesses. Keep a record of what each guess rules out. Accuracy matters more than rushing.
Controls
Use the keypad with mouse or touch, or keys 1–6, Backspace and Enter. English and Portuguese are selectable. Sound is optional.
FREE and COMPETITOR
The complete local game, practice, daily challenges and personal records are free. World rankings can be viewed on demand. COMPETITOR costs US$2 once per game through the official itch.io contribution checkout. Sign in with itch.io and restore an existing purchase before paying again. Qualifying purchases are verified on the server and associated with the authenticated account and game.
Official daily attempts use server-issued challenges and replay validation. The server recomputes the result and records one official attempt per account and UTC date. Rankings contain real submitted scores only. Local records remain personal and unverified. Local gameplay makes no API requests per move; official results are submitted at the end. Purchase recovery and rankings run only when needed.
Daily challenge and local storage
Players using the same version and UTC date receive the same local challenge. Records persist in the same browser when storage is available. Clearing browser storage, changing device clocks or changing browsers can affect local records. Official attempts are separately limited on the server.
Real gameplay
Jogue gratuitamente
Jogo completo, treino e desafio diário gratuitos. Selecione PT dentro do jogo. Para competir oficialmente, entre com itch.io e restaure sua compra COMPETITOR de US$2 por jogo.
About the game
Entertainment by QuantMatrix Games. This is a puzzle, not a clinical assessment or a promise of cognitive improvement. Version 1.1.0. Released October 31, 2026.