Sea Invaders

You control a small ship at the bottom of the screen. Your job is to shoot the waves of sea creatures swimming down from the top. You move left and right, firing upward, trying to clear each formation before they reach you. Some enemies drop power-ups when destroyed, which can change your weapon for a short time. The pace is steady, and the difficulty increases as you progress through the levels. It feels like a direct, uncomplicated test of your reflexes and aim.