There are 4 Super Moves / Super Powers in Knack 2. Finding all their locations unlocks the "Super Move Master" trophy.

None of them are missable! You can still get them via chapter select (world map) after the game. The first one cannot be missed. The other 3 are optional and fairly well hidden.

#1 - Crystal Swords - 0:05
Chapter 4-1, cannot be missed.

#2 - Shockwave - 0:46
Chapter 5-4, when entering the museum, near end of chapter, after growing big enough to open the door on the plaza. There's a wall straight in front of you after entering the museum that can be climbed as small Knack.

#3 - Storm - 1:16
Chapter 8-2, when you have to move the 3 colored boxes (purple, green, blue). Push the blue box on the blue platform. This opens a gate above the green box. Jump from the green box to the path upstairs. Now continue as small Knack. There are a bunch of invisible platforms on the path ahead, but you can throw a boomerang (Triangle) to reveal them. The super move is on that path.

#4 - Crystal Blast - 2:38
Chapter 12-3, pretty late into the chapter you'll see an enemy with a purple shield shooting at you from the distance and he cannot be killed. There's a platforming section right after this enemy (some moving plates and electricity coils). In order to progress you need to jump onto a big screw-platform. As the platform goes up, you can jump off the right side as small Knack. You should see some yellow sunstones that highlight the path where you can jump off. At the end of this secret passage is the 4th and final super move.