I've seen all those pictures before, but the difference for the N64 always amazes me.
It's like it's a different system. The final game (OoT) is infinitely better than the tech demo was. They developed that simultaneously with Mario 64, which obviously shows. The demo to Majora's Mask is just incomparable. GameCube's games also show clear improvements over the tech-demo.
If that trend continues (and I'm betting it does), we're in for a treat. The 2011 demo already looked pretty good, but that was just Twilight Princess in HD with some fancy lighting basically. Imagine what the actual WiiU game is going to look like with a new engine built from the ground up! Screw Unreal 4, Zelda WiiU's where it's at
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