Look Around with the Right Stick
Crash 4 allows you to shift the camera a bit using the right analog stick. There are many boxes hidden off-screen that can be spotted with the right stick, so if you’re going for the Box Gem, it’s a good idea to check above stacks of boxes with this before you go ahead and smash them all.
Use the Level Stats Screen to Quickly Select a Level
The Dimensional Map is awesome, but it can take a while to get from one side to the other, or just to find a station to get to the Flashback Levels. A much faster way to do this is to use the Level Stats screen. Here you can navigate the levels with a menu interface that also tells you more about your progress in a level at first glance. You can even access this while in the middle of another level!
You can find the Level Stats menu in the Pause Menu, or by pressing your console's equivalent to the Select Button.