That's just cold

"Chill out and beat a level using only Sunflowers and Ice-related plants."

is an achievement from Plants Vs. Zombies: The Next Levels. You gain it using only Sun-producers and Ice Plants.

Strategy

 * It's recommended to purchase the Chilly Pepper from Espio's Emporium. It can do a lot of damage and freeze zombies.
 * Get Power Flower as well. Another good One-Use Plant would be the Insertberry Plant with three Iceberg Lettuces. That can easily freeze a zombie permanently.
 * Generate a Snowflake-shroom too. That will very much help.

Trivia

 * Coffee Bean is also aloud. Without it, Ice-shroom and Snowflake-shroom would be pointless.
 * It is a pun on the sentance "That's just mean/rude".