Mermaid Puppy Undersea Game Start Screen

A bright, whimsical 3D underwater mobile game start screen inside a rounded-rectangle app frame, designed in a polished children's casual game style. The setting is a sunlit ocean floor with turquoise water, caustic light rays streaming from above, and soft floating bubbles over pastel sand. [On the right side]: A cute 3D mermaid puppy character floating upright, featuring cream and light tan fur, large expressive violet eyes, floppy ears with teal accessories, a tiny purple seashell necklace, and a shimmering mint-green mermaid tail. [On the left side]: Clean, modern UI typography. At the top, a small header reads "[海底救援开始啦]". Dominating the center is a massive bold title in dark navy reading "[泡泡湾人鱼狗救援队]". Below it, a playful subtitle reads "[和小汪一起收集贝壳、帮助海龟、点亮灯塔。]". Near the bottom left, three horizontal pill-shaped buttons: a yellow primary button labeled "[开始]" with a play icon, a white secondary button labeled "[选关]" with a target icon, and a white secondary button labeled "[贴纸]" with a star icon. A small circular settings button with a gear icon sits in the top-right corner. [Environment details]: 1 purple rock arch on the far left, 1 pink starfish on the left coral, 1 lavender clam shell near bottom-left, 1 large pink branching coral in the center foreground, 1 pink shell near bottom-right, 1 orange starfish on the sand, 1 blue porous rock in the right foreground, 1 blue tube coral cluster at the far right, and a tall pink-and-purple coral tower with an adjacent orange flower coral behind the puppy. [Style & Lighting]: Premium 3D cartoon render, glossy vinyl and toy-like textures, soft pastel palette of aqua, lavender, peach, and coral pink, gentle depth of field, warm and inviting atmosphere.