Rage inducing in a good way :) Best I could do is 7 dots.
In all levels after 1 the game should announce success if only 1 dot is left, as it will be hit sooner or later. Including a time slider would be nice, so you can speed up the simulation while waiting for eventual lucky hits after you realize you completely failed at predicting an actual path. There's a glitch that happens sometimes - the arrow slides along the edge for a few moments instead of bouncing right back.
All in all, very simple yet very effective.