Tunnels is the fifth level of Doorhaven. It introduces a much more complex situation than the previous levels while teaching the player to use logic to narrow down their options.

Description

Now, I know this looks like a sudden jump in complexity. And, it sort of is. However, there are sometimes moves you can make that will open a door at no net expense! Identifying moves like that will be useful for later puzzles.

Puzzle Logic

Opening a door with the same colored key behind it is a net gain for the player in this scenario, because it removes an obstacle without affecting the player's key count. As long as the player always makes this kind of move as soon as it is available, the puzzle will be easy to solve.

Solution

1. Pick up the white key.

2. Open the bottom white door and pick up the white key.

3. Open the white door and pick up the orange key.

4. Open the top orange door and pick up the orange key.

5. Open the bottom orange door and pick up the white key.

6. Open the white door and pick up the blue key.

7. Open the bottom blue door and pick up the blue key.

8. Open the blue door and pick up the two orange keys.

9. Open the orange door and pick up the white key.

10. Open the other orange door and pick up the white key.

11. Open both white doors and touch the goal.