The gold standard of game breakdowns continues to be PannenKoek’s extremely detailed and approachable examinations of Super Mario 64, but there’s other people out there are also nerding out excessively over games.
Suuper W‘s makes videos about several different Mario games, but Mario Kart is their primary beat. They recently explained how Mario Kart DS detects when you’ve hit a wall. It’s worth a look if you want to either how the detection works, how it can be abused, or, just possibly, both. (14 minutes)
Also of interest is a video they’ve done about “Wall Assisted Super Bouncing,” a Mario Kart DS technique that can cause you to game big air and leap over barriers under the right conditions. It’s 11 minutes, and even if (as is likely) you’re not in the Mario Kart DS TAS speedrunning scene, it may be interesting for its look at the specifics of MKDS’s engine.