The grid starts with some numbers already filled in — these are
clues and cannot be changed. Your job: fill the
remaining empty cells so that every row, every
column, and every 3×3 box
(marked by the thick dark borders) contains the digits
1 through 9 exactly once.
For example, if a row already has a 5, you cannot
place another 5 anywhere else in that row — or in its column or box.
// CONTROLS //
Click any empty cell, then tap a number — or press 1–9
Press Backspace or tap ⌫ to erase
Use the arrow keys to move between cells
Press H to use a hint
Selecting a cell highlights its row, column, and box —
and all matching numbers glow blue to help you scan
// MODES //
NORMAL — place a wrong number and it counts as a
fault. Three faults and the engine breaks down — game over.
No clock pressure, just take your time.
SURVIVAL — five-minute countdown. Right answers
buy you +5s, wrong answers cost −15s,
and hints cost −30s. Solve a board to load a fresh one;
keep going until the boilers run cold.
// HINTS //
Three hints per game. A hint reveals the correct number in your
currently selected cell — or in a random empty cell if nothing is
selected. The revealed cell flashes gold so you
can spot it.
RANK UP
[ ENGINEER_LOG ]
// RANK //
APPRENTICE
0 / 100 XP
// STATISTICS //
// ACHIEVEMENTS //
[ SUPPORT_THE_WORKSHOP ]
Enjoy the engine? Fuel the workshop with a small donation.
Every contribution keeps the gears turning.