Every lock is a row of steel wheels, each with one glowing notch. Roll every notch onto the bright bolt line across the middle. A wheel on the line turns green, and when every wheel is green the bolts slam back and the vault opens.
Drag a wheel up or down to roll it one notch at a time, or tap above or below the line on a wheel for one step. On a keyboard, ←/→ pick a wheel and ↑/↓ roll it.
Brass gears link neighbouring wheels. Rolling a wheel also rolls the wheel its gear's arrow points to: the same way, the opposite way, or two steps for one (×2). Gears pass a roll along a chain, and in a loop every roll moves every wheel in it. A smooth locked wheel can't be rolled by hand, only through its gear. Press a wheel to see which others will move.
Moves: the brass plate on the vault door shows your moves, the lock's budget and its par (the fewest moves that open it). Open a lock at par for a Clean Crack. Run out of moves and an alarm trips: the lock opens itself to show you the answer. Undo takes back a move but doesn't give it back to the budget.
The clock starts at 75 seconds. Every lock you open adds 20 seconds, and a Clean Crack 10 more. If it runs out, an alarm trips and the clock restarts at 40 seconds. Three alarms and the run is over.
A run is 17 locks. Each new kind of gear gets a short first lock, then a harder one: straight gears, crossed gears, chains, loops, locked wheels, ten-position drums, the 2-for-1 gear, and finally a six-wheel vault.
Scoring: each lock opened scores 300 × its number, plus 150 for every move left in the budget, ×1.5 for a Clean Crack. Open all 17 locks and every second left on the clock adds 20, and every alarm left 1,000.
Keys: Z undo, P pause, M mute, Enter presses Play.
