You're looking back at it with historical knowledge. A lot of Nintendo's games either set or raised the bar at the time of release. Sometimes, they were exceeed later. Examples:
Nes: Super Mario 3 pushed the Nes so hard that it needed a built in chip (called the MMC3) to run the game. According to Nintendo, the bottom screen was actually a split screen.
Super Nes: Again, Yoshi's island needed the SFX chip to pull off the effects. Rolling environments, scaling and rotation, polygonal effrects. Not an easy feat on the 16-bit console. DKC had the rendered sprites but Yoshi was pulling off effects that Donkey Kong wasn't even attempting.
N64: Wave Race and its water effects were never equalled during the entire gen. Majora's Mask was running side by side with PS2 games and, while not as impressive now, looked absolutely stunning among other games. It required the Expansion Pak to run *just like DK64
Gamecube: Twilight Princess went head to head with RE4 for the graphics crown on Gamecube. It was even a launch title for the Wii with virtually no upgrades and still praised for its graphics. Again, standards have changed so what impressed then doesn't impress now. We focus on different things.
Wii: Mario Galaxy? Metroid Prime 3? Skyward Sword!? Brawl!?
