The level objectives are displayed in the pre-level pop up and at the top of the level. To clear the level, you need to meet the level objective. Each level can have one or more of the following objectives.
Defeat the enemies
Clear the level by defeating all of the enemies. Some of the lizards can be stunned and removed with fruit matches, but the tougher enemies require you to hit them with Nibblers, even multiple times. Beware of the fishing lizards, they can catch your Nibblers and destroy them!
Clear the mud
Clear all the mud tiles in the level with fruit matches or by using Nibblers. Two-layer mud tiles need to be hit twice.
Collect the set amount of fruit in the level, by making matches and using Nibblers.
Rescue the fish
Free the helpless fish by leading them to water. If the fish is in a bucket, you need to break the bucket by matching fruit next to it or by hitting it with a Nibbler before the fish is freed.