This means that you have to get the "Perfect" rating (or equivalent) on every "action" challenge in a single level. You may get this naturally while you play through the game. The end of level result screen is slightly misleading. Instead of saying "Perfect" on the result screen, they should have called it "Completed" because it only tracks the number of events you completed which is not the same as getting perfect.
Basically every time you get to an action event, it puts up the icon on the right side of the screen and under that icon is a green bar that slowly shrinks. First make sure you are on easy as that will decrease the speed the bar shrinks. Now just complete the action before that green bar moves too much and you will get credit for a perfect. I think (although there is no way I can be sure) that as long as the word that pops up is blue, you get credit for the perfect. So Perfect, Excellent, Awesome, etc... count. I know Alright, So-So, Pretty Good, Nice, OK and Flubbed do NOT count.
If you do not get this through regular play to make this quick and easy, I'd recommend putting the game on Easy and then playing level 2. There are only 3 challenges in this level and they are easy motions to complete. You have a climb event, a throw event and a balance event. Just keep replaying until you get all blue comments.