Gold coins
There are three gold coins hidden in every level. A certain number of them must be collected in order to advance to the next campaign chapter. You also will be given diamonds as a reward for about every ten gold coins collected. Do not advance to the next level until you have collected all of the coins. There are also diamonds hidden in certain levels. These are indicated by a diamond silhouette at the level selection screen.
Layout
There are various objects that you can interact with in each level. Wooden crates can be pushed around. When dropped in water, they will float. Bombs and saws can destroy them. Some crates may be made of metal instead of wood. Those types will not float and cannot be destroyed. Turrets resemble small boxes armed with a grey cannon. They will repeatedly fire poison globs. Turrets can be pushed around to get them out of the way. If a poison glob pass over a bonfire, it will become an explosive shot. Bonfires can burn you to death if you come into contact with them. Bombs create explosive blasts in a "plus" pattern when they are touched. They can be used to destroy almost all objects, including trees, saws, and cracked rocks. If enter a web, any nearby spiders will appear. To escape a web, move twice quickly.