Place drag a piece from the tray onto the board.
Move drag a piece. Hold Ctrl to snap to the grid.
Rotate mouse wheel, Q / E, or drag the round handle. Hold Shift for fine control.
Nudge arrow keys (Shift = 10 units).
Remove double click, right click, Delete, or drag it off the board.
Locked pieces (dashed gold ring) can be rotated but not moved.
Targets the ring colour shows which light is needed. A solid centre means pure: no other colour may touch it. ×N means focused power.
Sensors (red eyes) must stay dark.