So, I was casually replaying this game on my ps3, and I found a movement trick that allows you to go slightly faster in free play.

When you roll and you switch characters, you move normally, but with no animation. And if you switch back to the character that rolled fast enough, the roll will reset, and rolling is the fastest way to move on the ground. I never saw this in the speedruns I watched but it might be useful in very large areas like the elephants area in the dead marshes level.