Play the Modern Playstyle First
The Retro Playstyle is great for old school Crash fans because it brings back the lives system, however Crash 4 is a very difficult game, as it assumes you’re using the Modern Playstyle and thus can afford to die a lot. Only use the Retro Playstyle if you’re very familiar and confident with the game, or enjoy the punishment of being sent back to the very start of the level.
Turn on Enhanced Shadows
Crash 4 allows you to enable an optional drop shadow with a yellow outline underneath your character. These are great at helping you judge Crash's position and speed in relation to where you want to land, and are similar to the drop shadows in the original PS1 games. With these on, you can take the guesswork out of tricky jumps, making it more about your precision and timing.
However if you're old school (and up for the challenge), you can turn these off in the Gameplay section of the Options Menu.