Pixel Art Vertical Asteroid Space Background

Vertical retro pixel-art space shooter background, [vertical 9:16] mobile game aspect ratio, designed as a seamless scrolling level backdrop. Deep outer space with a dark navy-to-black starfield and a [wide empty vertical corridor] for gameplay. Two luminous blue nebula streams run vertically along the left-center and right-center margins with speckled cyan particles, tiny bright stars, and subtle star glints. Asteroid field containing [34 visible asteroids] with dark charcoal rocky surfaces and rim lighting in [electric blue and deep navy]: 1 huge cropped asteroid in upper-left corner, 1 huge cropped on mid-left edge, 1 large near lower-left edge, 1 large cropped at bottom-left, 1 large near upper-right edge, 1 large near mid-right edge, 1 large cropped on lower-right edge, 1 large near bottom-right, plus 26 smaller asteroids flanking the sides to leave the center open. In the [upper-right quadrant], include a large cropped blue planet with a glowing atmospheric rim, curved horizon, and bright cyan edge light. Crisp 16-bit inspired pixel art, high contrast, sharp edges, no blur, no UI, no spaceships, no characters, no text.