animated characters, Cuphead and Mugman, co-op gameplay, online multiplayer, vibrant colors, 1930s cartoon style, exaggerated expressions, running, shooting, dodging, boss battles, vintage grain texture, rubber hose limbs, watercolor backgrounds, forest level, whimsical music notes, dynamic lighting, side-scrolling action, split-screen view, high-energy action, detailed character design, inkwell isle, whimsical, retro, hand-drawn animation, 2D platformer, challenging gameplay, seamless online connection.