These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Mach Schnell from 2 seems designed to have as many traps for the player as possible. It has the "Stairway in the Sky," an extremely long series of jumps across uneven blocks with no rails at all, it has a tempting shortcut which will make you go flying into the distance if you aren't prepared, and several precision jumps. That course is designed to kill anyone who holds down the accelerator.
Rollercide will make you bonk your head on all the checkpoints the first time you play it. There are grapples hidden beneath the track to prevent this, but they're hard to spot and might not work.