Comet Observatoryさんのイラストまとめ

"HomePlanet" is Super Mario Galaxy's starting planet in its E3 2006 Demo. Despite going unused, it remained in the game's files.

Even low-poly versions of the planet exist (bottom-right).

Background images promoting Super Mario Galaxy 2 that were used in the official Wii YouTube Channel back in 2010.

Rosalina & Luma's entry on the official Super Smash Blog was on October 31st, one day off from Super Mario Galaxy's 11th anniversary, which is on November 1st.

Super Mario Galaxy's Spring Mario (left) is reminiscent of "Bouncy Wario" (right), a transformation present in the Wario Land series, both work and look similar.

Puzzle & Dragons: Super Mario Bros. Edition contains some unique renders for Super Mario Galaxy related Power-ups and Characters.

Here are some examples:

Super Mario Galaxy 2's Supermassive Galaxy is located in World 4, and World 4 in Super Mario Bros. 3 was named Giant Land, which this galaxy is very similar to.

Super Mario Galaxy's Cosmic Mario shares its voice clips with the Cosmic Clones, suggesting that they could be related.

Mario has a lot of unused animations in Super Mario Galaxy, the most odd being sets of different tennis moves.

@Kenrulei Power Stars (left) & Super Stars (right) are different things, Power Stars were first introduced in Mario 64, and Super Stars were first introduced in Super Mario Bros. . One's a collectible and the other is a power-up.

- Mod Kiz3r

Chain Chompikins (left) from Super Mario Odyssey resembles Super Mario Galaxy's Gold Chomp (right), differences being it's overall texture, hat and leach.