Drag back the sling, release to fire a parabolic shot, and knock out every target on the level with the fewest stones.
A sling sits on the lower-left of the screen. Touch and drag from the loaded stone — the further you pull (and the more in the opposite direction of where you want the stone to fly), the harder the throw. A dashed arc previews the predicted trajectory under gravity. Release to fire. Hit every target on the level to advance: bonus for unused stones, level number multiplies the score. Run out of stones with targets still standing and the run ends.
Read the arc before releasing. The dashed preview line shows EXACTLY where the stone will go under gravity if you release now. Don't release on instinct — adjust the pull until the arc lands on a target, then let go. A two-second pause to aim is worth far more than a fast shot that misses.
Pull at an angle that exploits gravity. A long flat pull launches the stone fast and low — fine for the closest targets. For targets behind cover or at the back of the screen, pull downward more so the stone arcs HIGH; gravity will bring it down right onto your target instead of sailing over the top.
Group targets with a single shot. If two targets line up along the same arc, a well-aimed stone can pass through both. Look at clusters before each shot — the bonus from saving a stone is bigger than the score from a single hit, so set up double-hits whenever you can.
Don't ignore the floor. The stone bounces off the ground (with reduced energy), so a low rolling shot can clear ground-level targets that are blocked from above by platforms. When direct line-of-sight is impossible, try a flat skipping shot.