Lights Out

Puzzle strategy:

Level 1
Press the square second to the end. Press the third square in the first row. Finally, press the first square.

Level 2
Press the second to the last square in the second row . Press the fourth square in the first row. Finally, press the second square in the second row.

Level 3
Press the first square in the second row. Press the fourth square in the fourth row. Finally, press the last square in the last row.

Level 4
Press the third square in the third row. Press the third square in the second row. Finally, press the third square in the first row.