See How The DS Was Able To Pull Off The Legend Of Zelda: Spirit Tracks In This Video
The DS Legend of Zelda games are some of the series' most forgotten. Eschewing traditional controls for a purely touched-based approach, both Phantom Hourglass and Spirit Tracks split the Zelda community. I for one love their dungeons designs, but think Phantom Hourglass had issues with the central dungeon you had to revisit multiple times, while Spirit Tracks felt too small for a Zelda game and had several frustrating segments. Its central dungeon, however, was pretty good.
Anyway, the latest episode of youtuber Shesez's series Boundary Break takes a look at some of the tricks that makes Spirit Tracks tick. While there's a classic movement trick pulled off here (moving the environment around an object instead of moving the object itself in order to simulate movement), there are some more interesting things to observe, such as several rooms reserved exclusively for your chats with a single side character, how objects in the world exist only when they're in your view (this is fairly common in video game and is known as "culling," but this is a pretty extreme case).