← → or A/D to move. Hold SPACE (or touch) to fire. P/Esc pauses.
Enemies swoop in and lock into a formation, then peel off to dive-bomb you. Hit them mid-dive for double points.
Green bosses can fire a tractor beam. Get caught and you lose a ship — but destroy that boss to rescue it.
Catch a rescued ship to fly two fighters at once — double firepower!