2D game background, sky only, for a tower-building game, cartoon stylized hand-painted sci-fi art. Deep space sky with bright stars, colorful nebula, a large blue planet glowing in the distance, a distant galaxy, floating space dust. Very tall vertical composition for camera scrolling upward. Seamless vertically. Sci-fi palette: deep blue, purple, cyan, silver stars, glowing nebula accents. Clean shapes. No ground, no buildings, no trees, no text, no letters, no numbers, no watermark, no logo, no frame, no border.