Boost

The Sonic Boost is a move used by Sonic the Hedgehog in the game Sonic Unleashed. To perform the Sonic Boost, the player will have to fill the "Boost Bar" in the bottom-left corner of the screen. The bar can be filled by collecting rings, performing the Sonic Drift (360/PS3 versions only), or stringing togethet rings, tricks, and attacks (Wii/PS2 versions only). While performing the Sonic Boost, Sonic gains limited invincibility and increased speed, plowing through enemies and object/obstacles but he'll still get hurt from hazards such as spikes. The Sonic Boost is limited by the energy in the Boost Bar; in the 360/PS3 version, the Sonic Boost can be performed at any time, even if there is a little bit of energy in the bar. In the Wii/PS2 versions, the bar is divided into three sub-bars (upgrades can increase the sub-bars to a maximum of six) and can only be performed when at least one of the bars is completely full. This move can also be used to collect rings that are just out of reach. As the rings will be attracted to Sonic, much like the Lightning Shield. There is also an upgrade found in Chun-Nan called the Air Boost Shoes (in the Wii/PS2 versions, Sonic already has all the upgrades). This upgrade can only be reached by also getting the Wall Jump Shoes in Spagonia. With the Air Boost Shoes, Sonic will be able to use the Sonic Boost in the air, as opposed to doing an ineffective Homing Attack. This is used to reach the next Day Stage. This also serves to help the player find hidden alternate paths.