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There is no single intended solution to this game.
Thank you. Being able to reduce the number of walls was completely unexpected, but I’ve decided not to fix it.
How did you do that?
I created a prototype with extra space at the bottom right to confirm that a solution existed, and then looked for ways to reduce that space.
What you need to do at Level 3 is the same as what you need to do at Levels 12 and 16. Level 2 is also almost the same, but Level 3 is primarily designed to explain the differences from Level 2.