How to play: Move with ← → or A D, fire with Space. P pauses, M mutes. On touch screens, drag on the battlefield to move — your cannon fires while you hold — or use the buttons. Blast the formation before it lands, hide behind the shields (they crumble!), and watch for the red mystery ship for bonus points. Once each wave an invader drops a pink spare ship — catch it for an extra life. Invaders also drop power-ups: the cyan ring gives you a temporary shield bubble that eats bombs, and the orange chevrons give you twin rapid-fire cannons for a few seconds. Clear 3 or more waves and you can post your name and score at the end.