Cold as Ice Achievement
Cold as Ice15
Smash through 100 obstacles using the Freeze Ray
This will probably come by playing through the game. The freeze ray appears often and there are several levels that require you to use the gun in some way in order to progress any further.
If you want to grind this out, level 9 requires you to use the gun and you can farm out the freeze ray smashes before you buy too many of the power-ups.