CardboardLuigi's Hell Zone XP

Originally, the Chinese translation of Kamek's threat to Mario in Super Mario Galaxy had him telling Mario to go to hell, which was removed later.

Top: in the intro to Super Mario Galaxy, Mario manages to hold onto Peach's Castle as it is lifted up into space. However, Kamek appears and blasts Mario away with the words "So long! Enjoy your flight!"

Bottom left: in the 2018 Chinese Nvidia Shield port of Super Mario Galaxy, Kamek tells Mario "永别啦!下地狱吧!", which translates roughly to "Goodbye forever! Go to hell!"

Bottom right: in the Nintendo Switch version, which was a new translation into Chinese, Kamek now says "你就给我在地上打滚吧!" which translates roughly to "Go roll on the ground!", removing the harsh wording of the original translation.

Source: chinesenintendo, cometobservatory

Illustration from an article in a 1993 issue of the Japanese Famitsu magazine, serving as a mock-up of a speculation about the future of video game presentation.

The article posits that if games using photorealistic imagery like Mortal Kombat are popular, but so are games with highly cartoony characters like the Mario series, then surely something combining the two styles into one (with cartoon bodies and live-action heads) would eventually emerge as well.

Source: Famitsu (Japan), Issue 222, 1993

Top: the snowy ground texture in Cool, Cool Mountain in Super Mario 64 is blurry and yellowish, not recognizable as anything specific.

Bottom: it turns out that it is actually a stock proto of a blanket from a commercial texture CD, made more blurry and recolored. Interestingly, the original blanket's color would also have fit for the purpose of making snowy ground, but the color was likely introduced to give some visual variety to the environment and to keep all ground in the course from being some shade of light blue.

Source: Render96, Leonard85026417

In Super Mario Sunshine, a commonly known glitch is the Dune Bud high jump, whereby a Dune Bud on Gelato Beach is sprayed and then Mario performs a Ground Pound in such a way that he is in mid-air when the Dune Bud activates. This results in Mario being launched so high up into the air that he takes several minutes to fall back down.

However, an interesting interaction of this glitch that actually reveals some of the inner workings of this game can be seen when it is performed directly after defeating the Wiggler boss, immediately before the Shine Sprite spawns. This is shown in the footage; note the unusual black sky during the cutscene.

The reason for this is that the skyboxes in this game (as in many other Mario games like Super Mario Galaxy) actually follow Mario instead of remaining fixed in space. When Mario is launched into the sky, the skybox follows him, so when the camera switches to showing the Shine Sprite, the sky is no longer visible from the ground, having been pulled upwards by Mario.

Source: linky628