In short, when you die you now have the option to go to the Leaderboard screen, where you'll show the top 10 highscores of everyone who played. 

Some levels have a slight redesign, giving you more than one option to pass and giving you a chance if it's your first time seeing that scenario. 

Collisions have been adjusted, and when being at the top of the screen the saw goes up faster, so it is no longer necessary to wait for it to go up.