1 Harder jumps
In the new version of Crash Bandicoot, the jumping mechanism became harder. This makes it very hard to land on the right object in some cases.
2 Landing is slightly faster
According to the analysis by one gamer, landing after the jump happens slightly faster in n.sane trilogy. This gives players less time in the air to make the right decision compared to the older version.
3 Shoving over tight platforms
In the n.sane trilogy, Crash can shover slightly over tight platforms as a result of landing. This could make it harder for players to land over tight platforms without falling.
4 You need adequate landing space
Due to the way collision was designed in the game, Crash and Coco need adequate landing space so that they don't fall. When the characters land on a platform, they slide a bit further thus causing them to fall if no adequate space was there.
5 Pill shaped collision box
In the early game, Crash used to land in a certain specific spot after a jump. In the new game, the collision box, or the landing area, is pill shaped so you might land successfully on the edge of a platform then fall. (See How to Win Time Trials in Crash Bandicoot 2 (PS4))
6 Your jumps must be very accurate
Based on the many changes in the jumping mechanism, your jumps must be very accurate, especially when you are trying to land on a small platform.
7 The old game wasn't that simple
The older Crash game wasn't that simple with its unforgiving environment. Now with the new difficult jumping mechanism, the game became much harder than it was. (See Why are mobile games popular?)