The disappearing platform is a gimmick that appears in the Sonic Boom series. It is a type of platform across gaps that can disappear and reappear.
The disappearing platforms are high-tech devices. Design-wise, they consist of two bars with hover-engines below them. These bars are connected by a transparent plate.
In gameplay, disappearing platforms act as unstable platforms. They are normally placed in long rows, forming short bridges over gaps and bottomless pits, but can also appear individually, forming stairs to be climbed. When stood on by a playable character, the disappearing plaform will fade away after a second, and then reappear a moment later, although it will disappear again if stepped on once more. The exact time that passes before its reappearance may depend on its location. Disappearing platforms are usually placed across pits or previous sections, meaning the player will get noticeably delayed if they fail to cross them in time. Since regular running is too slow, the player must use the Sprint to cross disappearing platforms in time. In addition, the disappearing platforms can sometimes block passages or the way to Boomerang Switches, meaning the player has to make them disappear on purpose.
Sonic Boom: Shattered Crystal
The disappearing platforms made their debut in Sonic Boom: Shattered Crystal. In this game, their bars with hover-engines are red while their connecting plate is light blue.
Sonic Boom: Fire & Ice
In Sonic Boom: Fire & Ice, the disappearing platforms remain mostly the same design-wise, the only difference being their colors, which have changed from red and light blue to orange and blue (to match the game's central theme surrounding fire and ice).