pixel art alien UFO enemy, strict top-down orthographic view, retro arcade style, minimalistic design, low detail, readable silhouette, simple shapes, small size friendly, compact flying saucer, small green alien visible inside glass dome, sci-fi mars invader, clean sprite, centered object flat colors, subtle pixel shading, high contrast edges, crisp pixels, transparent background, isolated object, game-ready asset, designed for 2D top-down shooter, no animation needed, visually readable at 32x32 or 64x64, slightly intimidating but stylized simple hovering UFO, circular metallic body, tiny laser cannon under UFO, glowing accents, consistent lighting from top no perspective, no side view, no realistic rendering, no blur, no cinematic lighting, no gradients, no detailed textures, no complex shadows, no background, no motion blur, no anatomy details, no oversized head, no extra limbs, no clutter, no highly detailed cockpit