Practice a past day's fort. Practice never posts a score.
Drag back anywhere on the beach and let go to fling a Pebble. Tap anywhere while it flies to use its trick. Pop every crab in the fort. Fewer Pebbles used means more stars; each spare Pebble is worth 10,000.
Keyboard: arrows aim, Space fires (and uses the trick mid-flight), R restarts, P or Esc pauses.
Erase every star, shell and score on this device.