A Gentle 6×6 Puzzle Solved with Shape Squeeze in 18 Steps

This 6×6 board rates as gentle (difficulty score 762). Solving it from scratch takes 18 logical steps, using 5 techniques: Single cell, Row/column exclusion, Adjacency clear, Region confinement, Shape squeeze. Every step below is forced: nothing here is a guess.

1. First, place a marker at F3. Region has exactly one open cell left. Placing here clears the rest of row 3, column F, and its region. Placing here also clears its 2 touching neighbours.
2. Next, place a marker at D4. Region has exactly one open cell left. Placing here clears the rest of row 4, column D, and its region. Placing here also clears its 2 touching neighbours.
3. Then, every open cell left in this region sits in row 1, so its marker has to land there; that clears every other open cell in the row.
4. After that, every open cell left in this region sits in column A, so its marker has to land there; that clears every other open cell in the column.
5. Now, every open cell left in this region sits in row 6, so its marker has to land there; that clears every other open cell in the row.
6. From there, place a marker at A5. Region has exactly one open cell left. Placing here clears the rest of row 5, column A, and its region. Placing here also clears its 1 touching neighbour.
7. Following that, every remaining candidate in this region touches B1 and C1, so whichever candidate ends up marked will clear them, and they can be ruled out now regardless of which one wins.
8. First, place a marker at E1. Region has exactly one open cell left. Placing here clears the rest of row 1, column E, and its region.
9. Next, place a marker at C6. Region has exactly one open cell left. Placing here clears the rest of row 6, column C, and its region.
10. Finally, place a marker at B2. Region has exactly one open cell left.

The key move here was Shape squeeze. Once you can spot that, this board falls quickly. ∎