Object: find your way through the maze by opening locks (marked by '??') on the way.

You can walk your man up, down, left or right.
You cannot step onto the brown walls.
Once you know the moves you can simply click the destination (select Select View/Options/Board/SmartMoves).
You cannot step onto the locks, but once a code is correct the man can step over the lock to the next empty position.

Each pair of question marks symbolizes a number lock which opens if you guess the 2-digit code correctly.
When your man is positioned next to a lock it will be highlighted (the black question marks will turn red).
Now an input field at the right border shows two red question marks.
Click the question marks repeatedly to key in the code of the number lock, then click the CHECK button.
If you guessed wrong you lose.
Instead of repeatedly clicking the code number you can also click one of the black digits of the number pad at the right border, which is much faster.
If you guessed right, the lock opens (the digits at the lock turn green) and your man can pass.

You win if you make it to the right border.

The secret codes start very simple (like 1,1,1,1,...) and get harder and harder to solve with each variant.
Each code is based on a relatively simple rule.
You get a few hints:
- When you approach the first lock, the solution is given (no need to click the CHECK button; your man can pass this lock without further ado).
- The title of the variant is a hint.
- The game text of a variant might give you even more help. (Try not to read the variant's game text. It might give away too much).
Some codes use the digits which are placed on some wall tiles.