There is one screen and the whole board is always inside it. No scrolling, no zooming, no camera at all. That is a deliberate constraint: to solve a puzzle you first have to be able to see it.
Three regions
The screen divides into three from top to bottom.
The top bar is semi-transparent and carries two things: the number of the level you are in, and the menu. Being semi-transparent is deliberate — it does not hide the top edge of the diorama.
The diorama takes about three quarters of the screen. The graph of nodes and paths sits on top of the painted scene. All of the level's information is here: threats, lines of sight, items, the exit.
The bottom bar holds your inventory (stone, key, coins), the undo button, and the button that turns the threat highlight on and off. The hint button lives here too. The move counter is written together with the goal ("3 / 9"), so you see the Master threshold throughout the level; the tray next to it holds the figures you take down.
In landscape and on wide screens
On the web, or when you turn the phone sideways, the layout changes: the diorama centres and the inventory and controls move to a strip on the right. The information is the same; only where it sits changes.
How a move is made
You point at the node you want to go to. If the node is connected and legal, you walk; if it is not, it is drawn dimmed and the tap does nothing. Which means making an illegal move is not even possible — what is illegal is not tappable in the first place.
You can see the outcome before you make the move. With a mouse, hovering over a node previews it and clicking carries it out. On a touch screen, the first tap previews and the second confirms. The preview shows where the caravan will end up, whether you will be caught, and which enemy will be taken down; the result comes from the same calculation as the engine's real turn resolution, not from an approximate guess. On the keyboard, focusing a node previews it and Enter carries it out.
You can switch the preview off in the settings; then on a touch screen a single tap makes the move. Switching it off affects only the move preview: the stone preview and the threat highlight stay on.
Long-pressing a node shows its information: its tags, any item on it, and the toll if it has one.
The threat highlight
With the highlight on, every line of sight is painted on the board, and what gets painted is exactly what the engine computes — not an approximation.
It starts on by default in act 1, because the player is still learning the rules. One tap turns it off, and it can be set permanently from the settings.