Boogie Bunnies

You need to match 3+ light blue bunnies to start a dance party four times in a single level. A level ends when you fill the bar at the bottom and get a "level up" message w/ a screen clear.

The easiest way to do this is to do it in classic mode. That way you control how much the bunnies advance. They move forward one row for each three bunny shots. Play normally but try especially hard to get the a light blue bunny match so a dance starts. When this happens, wait for the dance to finish before you shoot more bunnies. You aren't going for points and if you get another light blue bunny match while a dance is going on I don't think it counts. If the bar gets close to filling up, let a bunny or two fall over the edge and it will go back down. Don't let too many fall, though, or the bar will empty out and it will be game over.

If you are going for the other achievements, there's no need to do a special run just for this achievement. You'll get a few crap levels with poor bunny layouts as you play and enough bunnies will fall for the level to drag out long enough to get the four dances.