Your goal is to lead all the frogs back to the water and create a Frog Corral. Move your mouse cursor over the frogs you want to move. Only the frogs that are inside the circle and flashing will move. Once you've decided which frogs to move, hold Left Click and drag to lead them where you want them to go. When you release Left Click, they'll stop moving. You'll know if all the frogs are in the water when the meter in the top right fills up completely, and the level ends. 

In some levels, doors will block your path. You can open a door by leading your Frog Corral onto a button of the same color. The number on the button tells you how many frogs are needed to press it down.

You'll also encounter friendly snails on your journey. You can push them by moving frogs into them. Snails are great for pushing buttons because they weigh more than your common frog.

Big red frogs also weigh more than common frogs. But be careful of the x-shaped cracks on the ground... their heavy weight will break right through!