Monsters vs Aliens

You can pretty much get this achievement in the second part of Chapter 1, where you're controlling The Missing Link for the first time. Grab every spherical enemy you see, with the B button, and make sure to toss them AWAY from any other enemy, by moving your aim, and then pressing RT to fire the enemy being held in a different direction. Do this with 25 enemies to get the achievement. If you haven't got this achievement by the time you're in the Leap Attack segment, boost the kills there, as the spherical enemies will infinitely respawn until you've done two Leap Attacks.

Pickup enemies with the B button and throw them away with the RT button.

Do this 25 times troughout the game to get this achievement

Easiest place is the end of level 10 on scene 2 due to the unlimited flow of robots.