Nebulaphile

Beat an extremely foggy level without disturbing any fog.

Strategy
The best way to get this achievement is on Level 4-9, because it's extremely foggy. To get it, you should pick the following (I don't have my DS, please edit, Garlic after beating Adventure Mode):

Puff-shroom

Sun-shroom

Fume-shroom with Gloom-shroom

Cactus

Lily Pad

Magnet-shroom

Wall-nut

As the achievement states, you can't use fog disturbers. If you have the Plantern or Blover, you can't achieve this; It isn't very different than any other level, so it can be beaten easily. 2 Gloom-shrooms are cheaper than Threepeaters, because it costs 325 sun. Cacti should take care of balloonists, but it can take care of enemies facing to its right, but once the balloonists makes through it, Cacti don't help!