9:36 it looks like Yoshi Valley is in the shape of Mario's face silhouette.

"why is there a theme of eyes and mouth" he asks about a game series that historically has eyes and mouth on practically everything

"Should we optimize the gameplay and framerate?"
"NO! MORE SEAGULLS!!!"

The strangest things about the vehicles on Toad's Turnpike is that they are programmed to travel almost every single course in the game if modded into them. They'll even fly across the jet ramp on DK's course, though they don't gain the speed boost and instead just kind of hover slowly across.

those seagulls have straight up hyperrealistic eyes

0:28 Half-Life Fans when they hear "fully modeled"

The Choco Mountain faces seem to simply be a continuation of the classic hills with eyes. It’s Mario, so basically anything has a face. As for whether or not it’s chocolate, it’s hard to say

1:28 Sleep paralysis demon Mario just staring at us in the corner

2:48 Very loosely remembering reading about this in the past: As to why there are eyes and mouthes on stuff in so many Mario titles (and just Japanese culture in general), if I recall correctly it's possibly a few different Shinto things that are deeply ingrained in Japanese culture. They believe all objects have a soul, or that objects cherished by their owner can develop a soul, or that objects older than 100 years develop souls. So that's also why pencil cases have faces, fridges have faces etc, random everyday objects get cute faces put on them - it's cute, and invokes the idea that everything has value and should be cared for/about.

"I couldn't even be bothered to count them all out for you"

28.  There's 28 vehicles.

"be not afraid" ahh seagulls

This video as a whole is a GREAT example on how the N64 does texture filtering.
Regular texture filtering gets four colors and do a mix between em, but nintendo to save some space on the chip decided to use only three colors, creating these "triangles", that do give it an unique paintbrush like aspect.

The camera flies up to the Choco Mountain “eyes” during the credits roll and you even get a good look in the attract/demo sequence. Bushes, clouds and everything have eyes in Super Mario World, Super Mario Bros 3, and other Mario games.

"Way back in 2016"
I'm not ready to feel this old

I actually have a theory about the seagulls. The fact they fly in so many different directions and orientations tells me the devs NEEDED depth to keep them from simply disappearing. Most other aspects of the game always face the player, hence no depth needed.

WHAT DO YOU MEAN THE BOULDERS IN CHOCO MOUNTAIN HAVE EYES AND A MOUTH?!?!?!  I've been playing this game for over 20 years and I never noticed this!!!

7:23 If you look at the manual, you can actually see a top-down perspective of every track as well as how many kilometers they all are. It's neat, but it also means that it was a very purposeful decision to make Rainbow Road and Wario's Stadium 3 times longer than an average track on the devs part.💀

I love that, even if it isn't a gameplay feature and just a cosmetic level design, Peach's Castle is the same in this game and SM64. I believe it's the two games out of the whole franchise that keeps the designs the same, including the surrounding scenery

1:22 Luigi and Bowser getting yeeted to the hypothetical Boo-plagued castle courtyard had me in stitches for more than I expected 🤣

10:40 you can also tell that they just put the model into the track, the grass color obviously changes.