animated character, Cuphead, expert mode, challenging pose, firing finger gun, intense expression, vintage cartoon style, exaggerated features, rubber hose limbs, bold outlines, vibrant colors, action-packed, boss battle background, flying bullets, parry attacks, platform elements, high difficulty, dynamic angle, dramatic lighting, 1930s animation aesthetic, grainy texture, cel-shading, side-scrolling view, energy beams, health bar indicator, devilishly hard, retro gaming, fast-paced, fluid animation, screen shake effect, power-up collectibles, in-game currency, run and gun, multi-phase boss fight.