Goal: Shade cells to build a connected canal network.
Rules:
• Each number = count of canal neighbours (up/down/left/right)
• All canal cells must connect into one region
• No 2×2 block of canal cells allowed
Controls:
• Click/Tap = fill canal (blue)
• Right-click/Long-press = mark land (X)
• Keys: 1=canal, 2=land, H=hint, R=restart, Esc=menu