In this scene the player evades a rolling boulder to get to a chest containing the bomb equipment item. There is a cracked wall on the boulders path that blocks the entrance to a little cave containing the third heart shard.

Boulder

During the intro cutscene the boulder is deactivated until the camera pans over to it. This is only done to make timing it a bit easier. It is controlled by the custom HeroBoulder script which moves it between the points defined in the Points field. When it reaches one of those points it fires the Stopped event and then waits for the CornerDelay.

The boulder carries a TriggerDamageSender that basically damages the player if they touch the boulder. Its Direction is set to SenderToReceiverXY which causes the player to be pushed away from the boulders center but into the ground or up into the sky. Whenever it hits something it calls Delay on the boulder script which stops the it and avoids just rolling over the player.