Board Thread:Wiki Management/@comment-4009269-20140409213003/@comment-24843494-20140421012038

Defeat a level with only one plant. No minecart moving allowed.

One Star: complete the challenge

Two Stars: complete the challenge, no lawnmowers lost

Three Stars: complete the challenge, no lawnmowers lost, no boosts

Four Stars: complete the challenge, no lawnmowers lost, no boosts, no power-ups

Impossible Star: complete the challenge, no lawnmowers lost, no boosts, no power-ups, no plant food(!)