Flowey, Undertale, boss fight, evil grin, petals spread, bullet-hell, green and white color scheme, vines, thorns, pixel art style, action pose, intense expression, multiple eyes, heart-shaped soul, red and yellow attacks, underground setting, dark background, glowing particles, dramatic lighting, high contrast, dynamic angle, close-up shot, digital effects, game interface elements, determination, player character dodging, vibrant energy blasts, chaotic environment, survival theme, fantasy, 8-bit music notes, retro gaming aesthetic.