Chaos Orbs (カオスオーブ Kaosuōbu?) are glowing gem-like objects that appear in the PS3/Xbox 360 version of Sonic Unleashed. When collected, these orbs increase Sonic the Hedgehog's/Sonic the Werehog's Experience.
Chaos Orbs resemble yellow, transparent, octahedron-shaped crystals and comes in different sizes. When collecting a Chaos Orb, it will increase Sonic's current Experience, which can then be used on the Status Screen to increase Sonic the Hedgehog's and/or Sonic the Werehog's parameters. Once a parameter level up, Sonic's abilities will increase and he can learn new skills as well (Werehog only).
Chaos Orbs can be collected from defeated enemies in the game, be it Dark Gaia's Minions or Eggman's Robots. Upon their destruction, the enemies will release a certain amount of Chaos Orbs which can be collected by Sonic. In daytime stages, all released Chaos Orbs will automatically home onto and be collected by Sonic, while in nighttime stages, Sonic the Werehog has to get close to the Chaos Orbs in order to collect them.
The amount of Experience each Chaos Orb grants is determined by its size, meaning that the larger the Chaos Orb is, the more Experience it will grant. Equally, the tougher the enemy is, the larger the Chaos Orbs will be when the enemy in question is defeated.