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curl-6 on 04 May 2015
It just occurred to me that Trine 2: Director's Cut is also a strong candidate.
Like the Zelda demo, it uses a contained presentation, namely 2D sidescrolling gameplay, to focus the system's rendering power. It takes a game that already looked beautiful on PS3 and 360, and amps up the textures, anti-aliasing, screen resolution, water effects, and destructibility.
