The Boost Object is a type of gimmick that appears in Sonic Rivals and Sonic Rivals 2. When utilized, it allows the user to perform Air Boost or Speed Boost which launches the user into the air or forward respectively.
The Boost Object is an environmental object that launches the player vertically or horizontally depending on which button is pressed, but if the player doesn't press the button quickly, he/she will simply vault over the panel, losing the opportunity to get launched, as well as losing all momentum.
Usually, the game shows the button prompt that best fits the current situation, but at other times, a question mark will appear. It is always possible to continue onwards no matter which direction is chosen.
The Boost Object made its first appearance in Sonic Rivals, where they appear in all the acts. Though a small object in general, the design of the panel will be different depending on the zone that is played. In the fight against the Egg Kong, the player can boost off some missiles that the Egg Kong launches to attack the player with, which will then stick to the ground upon landing.
Sonic Rivals 2
The Boost Object appears in Sonic Rivals 2 in all Zones, where all the characters can use it. It has the same characteristics and effects as in Sonic Rivals.