The game behaves like traditional Go, except when a move captures a group of stones, all the stones doing the capturing "fall" down.
The capturing stones continue to fall until they hit a non-falling stone, or reach the end of the board.
This can cause a previous strong group of stones to become weak after capturing. (Eyes can collapse, long groups can collapse into one big blob)
In true Puyo Puyo fasion, falling stones can chain attacks.