crossover, Deltarune characters, Undertale characters, Frisk, Kris, action pose, fighting stance, pixel art style, vibrant colors, underground setting, heart motifs, determination, SAVE points, Flowey, Ralsei, dynamic lighting, side view, battle scene, magic spells, colorful projectiles, retro game aesthetic, determination, friendship themes, Toby Fox's style, chiptune soundtrack, 8-bit, 16-bit textures, fantasy environment, monster encounters, bullet hell elements, indie game homage, split screen, character contrast, iconic symbols, determination soul, checkerboard floor, determination, ambient light, dramatic shadows.