To increase the stability without spending all the available wood, some levels feature a bungee-rope that can be connected to the anchor-points of the planks. Some levels on the other hand don't feature any anchor-points at all at the start. In these cases, the player has to look for destructible scenery in order to create anchor-points. And other levels even require the player to change the location of the sun to influence the water-level and reveal new anchor-points.
While the level is already completed once all the animals are safely across, to really master a level, the player has to do it using the least amount of planks and at the same collect all the golden eggs that are scattered around the level and may not be on the easiest path over the gap.
Lead Game Design